Set<Id> setCaseRTId = new Set<Id>();
for(case c : newCases) {
    setCaseRTId.add(c.recordTypeId);
}
Map<Id, RecordType> caseMap = new Map<Id, RecordType>([ SELECT Id, DeveloperName
                                    FROM RecordType WHERE SObjectType ='Case' AND Id = :setCaseRTId]);
System.debug('Map Values ? : '+caseMap);