How can I retrieve the information of a Sim card if it is changed in one of the dual Sim slots?

You can use this working sample code for solving your problem.

Reference link: https://github.com/ITger/DualSIMCard

Example code from class: https://github.com/ITger/DualSIMCard/blob/master/dualSIMcardReader/src/main/java/pl/itger/dualsimcard/TelInfo.java

    /**
     * Created by piotrz on 7/23/15.
     * Copyright 2015 Piotr Zerynger ITger
     */

    import android.content.Context;
    import android.telephony.CellInfo;
    import android.telephony.TelephonyManager;
    import android.telephony.gsm.GsmCellLocation;

    import java.lang.reflect.Method;
    import java.util.ArrayList;
    import java.util.List;

    import static pl.itger.dualsimcard.MainActivity.getMActContext;

    public final class TelInfo {

        private static TelInfo telInf;
        protected Sci[] scitems;
        ArrayList<Sci> scitemsArr;
        //private String imsiSIM1;
        private String imsiSIM2;
        private boolean isSIM1Ready;
        private boolean isSIM2Ready;
        private String sim1_STATE;
        private String sim2_STATE;
        // Integrated circuit card identifier (ICCID)
        private String sim1_ICCID;
        private String sim2_ICCID;
        // International mobile subscriber identity (IMSI)
        private String sim1_IMSI;
        private String sim2_IMSI;
        // Service provider name (SPN)
        private String sim1_SPN;
        private String sim2_SPN;
        // Mobile country code (MCC)
        private String sim1_MCC;
        private String sim2_MCC;
        // Mobile network code (MNC)
        private String sim1_MNC;
        private String sim2_MNC;

        //private NeighboringCellInfo nci;

        //private  List<NeighboringCellInfo> sim1_NC;
        //private  List<NeighboringCellInfo> sim2_NC;
        private String sim1_MCC_MNC;
        private String sim2_MCC_MNC;
        // Mobile subscriber identification number (MSIN)
        // Mobile station international subscriber directory number (MSISDN)
        private String sim1_MSISDN;
        private String sim2_MSISDN;


        // Abbreviated dialing numbers (ADN)
        // Last dialed numbers (LDN)
        // Short message service (SMS)
        // Language preference (LP)
        // Card holder verification (CHV1 and CHV2)
        // Ciphering key (Kc)
        // Ciphering key sequence number
        // Emergency call code
        // Fixed dialing numbers (FDN)
        //getDeviceId() Returns the unique device ID, for example, the IMEI for GSM and the MEID or ESN for CDMA phones.
        private String sim1_IMEI;
        private String sim2_IMEI;
        // Local area identity (LAI)
        private String sim1_LAI;
        private String sim2_LAI;
        // Location Area Code (LAC).
        private String sim1_LAC;
        private String sim2_LAC;


        // Own dialing number
        // Temporary mobile subscriber identity (TMSI)
        // Routing area identifier (RIA) network code
        // Service dialing numbers (SDNs)
        // CellID
        private String sim1_CellID;
        private String sim2_CellID;
        private List<CellInfo> all;


        private TelInfo() {
        }

        /*@
       @requires context != null;
       @ensures TelInfo != null;
          @*/
        public static TelInfo getInstance() {//Context context) {
            //if (TelInfo.telInf != null) {
            TelInfo.telInf = null;
            TelInfo.telInf = new TelInfo();
            //}
            Context context = getMActContext();
            //printTelephonyManagerMethodNamesForThisDevice(context);
            //System.out.println("1 " + context);

            TelephonyManager telMngr = ((TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE));
            //System.out.println("2 " + telMngr);

            //telInf.nci = new NeighboringCellInfo(NeighboringCellInfo.UNKNOWN_RSSI, new GsmCellLocation().toString(), TelephonyManager.NETWORK_TYPE_HSPA);
            //System.out.println(telInf.nci.toString());


            telInf.sim1_ICCID = telMngr.getSimSerialNumber();
            telInf.sim1_IMSI = telMngr.getSubscriberId();
            telInf.sim1_SPN = telMngr.getSimOperatorName();
            telInf.sim1_MCC = telMngr.getNetworkCountryIso();
            telInf.sim1_MNC = telMngr.getNetworkOperatorName();
            telInf.sim1_MCC_MNC = telMngr.getSimOperator();
            telInf.sim1_MSISDN = telMngr.getLine1Number();
            telInf.sim1_IMEI = telMngr.getDeviceId();
            //telInf.sim1_NC = telMngr.getNeighboringCellInfo();

            if (telMngr.getPhoneType() == TelephonyManager.PHONE_TYPE_GSM) {
                final GsmCellLocation location = (GsmCellLocation) telMngr.getCellLocation();
                if (location != null) {
                    telInf.sim1_LAC = Integer.toString(location.getLac());
                    telInf.sim1_CellID = Integer.toString(location.getCid());
                }
            }

            telInf.imsiSIM2 = null;

            telInf.isSIM1Ready = telMngr.getSimState() == TelephonyManager.SIM_STATE_READY;
            telInf.isSIM2Ready = false;

            telInf.sim1_STATE = simState(telMngr.getSimState());
            try {
                //telInf.isSIM1Ready = getSIMStateBySlot(context, "getSimState", 0);
                telInf.isSIM2Ready = getSIMStateBySlot(context, "getSimState", 1);
                //System.out.println("!!");
            } catch (ITgerMethodNotFoundException e1) {
                //Call here for next manufacturer's predicted method name if you wish
                e1.printStackTrace();
            }

            if (telInf.isSIM2Ready) {
                try {
                    // telInf.sim1_IMSI = getDeviceIdBySlot(context, "getDeviceId", 0);
                    telInf.imsiSIM2 = getDeviceIdBySlot(context, "getDeviceId", 1);
                    telInf.sim2_ICCID = getDeviceIdBySlot(context, "getSimSerialNumber", 1);
                    telInf.sim2_IMSI = getDeviceIdBySlot(context, "getSubscriberId", 1);
                    telInf.sim2_SPN = getDeviceIdBySlot(context, "getSimOperatorName", 1);
                    telInf.sim2_MCC = getDeviceIdBySlot(context, "getNetworkCountryIso", 1);
                    telInf.sim2_MNC = getDeviceIdBySlot(context, "getNetworkOperatorName", 1);
                    telInf.sim2_MCC_MNC = getDeviceIdBySlot(context, "getSimOperator", 1);
                    telInf.sim2_MSISDN = getDeviceIdBySlot(context, "getLine1Number", 1);
                    telInf.sim2_IMEI = getDeviceIdBySlot(context, "getDeviceId", 1);

                    if (telMngr.getPhoneType() == TelephonyManager.PHONE_TYPE_GSM) {
                        final GsmCellLocation location = getCellLocBySlot(context, "getCellLocation", 1);// telMngr.getCellLocation();
                        if (location != null) {
                            telInf.sim2_LAC = Integer.toString(location.getLac());
                            telInf.sim2_CellID = Integer.toString(location.getCid());
                        }
                    }

                    System.out.println("!");
                } catch (ITgerMethodNotFoundException e1) {
                    //Call here for next manufacturer's predicted method name if you wish
                    e1.printStackTrace();
                }
            }

            telInf.scitemsArr = new ArrayList<Sci>();

            telInf.scitemsArr.add(new Sci("SIM 1 state", telInf.sim1_STATE));
            telInf.scitemsArr.add(new Sci("Integrated circuit card identifier (ICCID)", telInf.sim1_ICCID));
            telInf.scitemsArr.add(new Sci("Unique device ID (IMEI or MEID/ESN for CDMA)", telInf.sim1_IMEI));
            telInf.scitemsArr.add(new Sci("International mobile subscriber identity (IMSI)", telInf.sim1_IMSI));
            telInf.scitemsArr.add(new Sci("Service provider name (SPN)", telInf.sim1_SPN));
            telInf.scitemsArr.add(new Sci("Mobile country code (MCC)", telInf.sim1_MCC));
            telInf.scitemsArr.add(new Sci("Mobile operator name", telInf.sim1_MNC));
            telInf.scitemsArr.add(new Sci("Mobile country code + mobile network code (MCC+MNC)", telInf.sim1_MCC_MNC));
            telInf.scitemsArr.add(new Sci("Mobile station international subscriber directory number (MSISDN)", telInf.sim1_MSISDN));
            telInf.scitemsArr.add(new Sci("Location Area Code (LAC)", telInf.sim1_LAC));
            telInf.scitemsArr.add(new Sci("Cell Tower ID (CID)", telInf.sim1_CellID));

            if (telInf.isSIM2Ready) {
                telInf.scitemsArr.add(new Sci(" ", " "));
                telInf.scitemsArr.add(new Sci("SIM 2 state", telInf.sim2_STATE));
                telInf.scitemsArr.add(new Sci("Integrated circuit card identifier (ICCID)", telInf.sim2_ICCID));
                telInf.scitemsArr.add(new Sci("Unique device ID (IMEI or MEID/ESN for CDMA)", telInf.sim2_IMEI));
                telInf.scitemsArr.add(new Sci("International mobile subscriber identity (IMSI)", telInf.sim2_IMSI));
                telInf.scitemsArr.add(new Sci("Service provider name (SPN)", telInf.sim2_SPN));
                telInf.scitemsArr.add(new Sci("Mobile country code (MCC)", telInf.sim2_MCC));
                telInf.scitemsArr.add(new Sci("Mobile operator name", telInf.sim2_MNC));
                telInf.scitemsArr.add(new Sci("Mobile country code + mobile network code (MCC+MNC)", telInf.sim2_MCC_MNC));
                telInf.scitemsArr.add(new Sci("Mobile station international subscriber directory number (MSISDN)", telInf.sim2_MSISDN));
                telInf.scitemsArr.add(new Sci("Location Area Code (LAC)", telInf.sim2_LAC));
                telInf.scitemsArr.add(new Sci("Cell Tower ID (CID)", telInf.sim2_CellID));


                //telInf.scitemsArr.add(new Sci("NC (Neighboring Cell ", telInf.sim1_NC.toString() ));

            }

            return telInf;
        }

        private static String simState(int simState) {
            switch (simState) {
                case 0:
                    return "UNKNOWN";
                case 1:
                    return "ABSENT";
                case 2:
                    return "REQUIRED";
                case 3:
                    return "PUK_REQUIRED";
                case 4:
                    return "NETWORK_LOCKED";
                case 5:
                    return "READY";
                case 6:
                    return "NOT_READY";
                case 7:
                    return "PERM_DISABLED";
                case 8:
                    return "CARD_IO_ERROR";
            }
            return "??? " + simState;
        }

        private static String getDeviceIdBySlot(Context context, String predictedMethodName, int slotID) throws ITgerMethodNotFoundException {

            String imsi = null;
            TelephonyManager telephony = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
            try {
                Class<?> telephonyClass = Class.forName(telephony.getClass().getName());
                Class<?>[] parameter = new Class[1];
                parameter[0] = int.class;
                Method getSimID = telephonyClass.getMethod(predictedMethodName, parameter);

                Object[] obParameter = new Object[1];
                obParameter[0] = slotID;
                Object ob_phone = getSimID.invoke(telephony, obParameter);

                if (ob_phone != null) {
                    imsi = ob_phone.toString();

                }
            } catch (Exception e) {
                e.printStackTrace();
                throw new ITgerMethodNotFoundException(predictedMethodName);
            }

            return imsi;
        }

        private static GsmCellLocation getCellLocBySlot(Context context, String predictedMethodName, int slotID) throws ITgerMethodNotFoundException {

            GsmCellLocation cloc = null;
            TelephonyManager telephony = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
            try {
                Class<?> telephonyClass = Class.forName(telephony.getClass().getName());
                Class<?>[] parameter = new Class[1];
                parameter[0] = int.class;
                Method getSimID = telephonyClass.getMethod(predictedMethodName, parameter);

                Object[] obParameter = new Object[1];
                obParameter[0] = slotID;
                Object ob_phone = getSimID.invoke(telephony, obParameter);

                if (ob_phone != null) {
                    cloc = (GsmCellLocation) ob_phone;

                }
            } catch (Exception e) {
                e.printStackTrace();
                throw new ITgerMethodNotFoundException(predictedMethodName);
            }

            return cloc;
        }

        private static boolean getSIMStateBySlot(Context context, String predictedMethodName, int slotID) throws ITgerMethodNotFoundException {
            boolean isReady = false;
            TelephonyManager telephony = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
            try {
                Class<?> telephonyClass = Class.forName(telephony.getClass().getName());
                Class<?>[] parameter = new Class[1];
                parameter[0] = int.class;
                Method getSimState = telephonyClass.getMethod(predictedMethodName, parameter);
                Object[] obParameter = new Object[1];
                obParameter[0] = slotID;
                Object ob_phone = getSimState.invoke(telephony, obParameter);

                if (ob_phone != null) {
                    int simState = Integer.parseInt(ob_phone.toString());
                    telInf.sim2_STATE = simState(simState);
                    if ((simState != TelephonyManager.SIM_STATE_ABSENT) && (simState != TelephonyManager.SIM_STATE_UNKNOWN)) {
                        isReady = true;
                    }
                }
            } catch (Exception e) {
                e.printStackTrace();
                throw new ITgerMethodNotFoundException(predictedMethodName);
            }

            return isReady;
        }

        public static void printTelephonyManagerMethodNamesForThisDevice(Context context) {

            TelephonyManager telephony = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
            Class<?> telephonyClass;
            try {
                System.out.println("-------------------------------");
                telephonyClass = Class.forName(telephony.getClass().getName());
                Method[] methods = telephonyClass.getMethods();

                for (Method method : methods) {
                    // if (methods[idx].getName().startsWith("get")) {
                    System.out.println("\n" + method.getName() + " declared by " + method.getDeclaringClass());//+ "  superclass " + methods[idx].getDeclaringClass().getSuperclass().getName());
                    //}
                }
                System.out.println("-------------------------------");
            } catch (ClassNotFoundException e) {
                e.printStackTrace();
            }
        }

        public boolean isSIM1Ready() {
            return isSIM1Ready;
        }

        public boolean isSIM2Ready() {
            return isSIM2Ready;
        }

        private boolean isDualSIM() {
            return imsiSIM2 != null;
        }

        @Override
        public String toString() {
            return "XXXXXXXXXXXXXXXX TelInfo{" +
                    "imsiSIM1='" + sim1_IMSI + '\'' +
                    ", imsiSIM2='" + imsiSIM2 + '\'' +
                    ", isSIM1Ready=" + isSIM1Ready +
                    ", isSIM2Ready=" + isSIM2Ready +
                    '}';
        }

        private static class ITgerMethodNotFoundException extends Exception {
            private static final long serialVersionUID = -996812356902545308L;

            public ITgerMethodNotFoundException(String info) {
                super(info);
            }

        }
    }

I hope this helps.