Set<String> SA = new Set<String>();
for(Contact a:Trigger.new){
    //filtering out dealer contact record type
    if (a.RecordTypeID !='012440000002T6J' && a.Account_Record_Type__c == 'Agency Establishment'){
        //something new
        SA.add(a.Agency__c);
        //a.Agency_Name__c = a.Agency__c; // the default agency name will be the SA
    }
    else if (a.Account_Record_Type__c != 'Agency Establishment' ){
        a.VOSS_Manager__c = null;
        a.NAIS_VSEN_Mgr__c = null;
        a.CBM__c = null;
        a.PSE__c = null;
        a.RVP__c = null;
        a.MTSS__c = null;
        a.Inside_Sales_Representative__c = null;
        a.VPSE__c = null;
    }
}

for (Territory_Reference__c t : [SELECT MTSS__c, AGENCY_DTT__c, NAIS_VOSS_Mgr__c, VSEN__c, NAIS_VSEN_Mgr__c, AGENT_DTT__c, AGENCY__c, AGENCY_ID__c, SA_DTT_KEY__c, VOSS__c, PSE__c, PSM__c, MSO__c, RVP__c, Area_Title__c, REGION__c, RMOS__c, ASD__c, CBM__c, VPSE__c, VSPM__c FROM Territory_Reference__c WHERE AGENCY_ID__c IN : SA]){
    Terr2Terr_SA.put(t.AGENCY_ID__c,t);
    Terr2Terr_DTT.put(t.AGENT_DTT__c,t);
    Terr2Terr_OC.put(t.AGENCY_DTT__c,t);
}

if (!Terr2Terr_SA.isEmpty()){
    for(Contact a:Trigger.new){
        if (Terr2Terr_DTT.get(a.Dtt__c) <> null && a.RecordTypeID !='012440000002T6J' && a.Account_Record_Type__c == 'Agency Establishment' && a.Establishment_Type__c != 'Open Coverage'){
            Territory_Reference__c  t2t = Terr2Terr_DTT.get(a.Dtt__c);
            //a.Agency_Name__c = t2t.AGENCY__c;
            a.Inside_Sales_Representative__c = t2t.VSEN__c;
            a.VPSE__c = t2t.VPSE__c;
        }

        if (Terr2Terr_OC.get(a.Dtt__c) <> null && a.RecordTypeID !='012440000002T6J' && a.Account_Record_Type__c == 'Agency Establishment' && a.Establishment_Type__c == 'Open Coverage'){
            Territory_Reference__c  t2t = Terr2Terr_OC.get(a.Dtt__c);
            //a.Agency_Name__c = t2t.AGENCY__c;
            a.Inside_Sales_Representative__c = t2t.VSEN__c;
            a.VPSE__c = t2t.VPSE__c;
        }


        if (Terr2Terr_SA.get(a.Agency__c)<>null && a.RecordTypeID !='012440000002T6J' && a.Account_Record_Type__c == 'Agency Establishment'){
            Territory_Reference__c  t2t = Terr2Terr_SA.get(a.Agency__c);
            //a.Agency_Name__c = t2t.AGENCY__c;


            a.VOSS_Manager__c = t2t.NAIS_VOSS_Mgr__c;
            a.NAIS_VSEN_Mgr__c = t2t.NAIS_VSEN_Mgr__c;
            a.CBM__c = t2t.MSO__c;
            a.PSE__c = t2t.PSE__c;
            //a.PSM__c = t2t.PSM__c;
            //a.RVP__c = t2t.RMOS__c;
            //a.VOSS__c = t2t.VOSS__c;
            a.RVP__c = t2t.RVP__c;
            a.MTSS__c = t2t.MTSS__c;
            a.Establishment_SA_Number__c = a.AGENCY__c;
            a.Establishment_Dtt__c = a.DTT__c;
            a.Establishment_Record_Type__c = a.Account_Record_Type__c;
            a.Establishment_Type2__c = a.Establishment_Type__c;
            //a.Xerox_Entity__c = t2t.REGION__c;
            //a.Area_Title_t2t__c = t2t.Area_Title__c;
            //a.ASD__c = t2t.ASD__c;
            //a.CBM__c = t2t.CBM__c;
            //a.VSPM__c = t2t.VSPM__c;
        }
    }
}