thanks friends for ur suggestions!
but my question was that if someone is an experienced 17th grade officer in isi his experience will be taken into consideration or not after qualifying css?
in a near past i met with a csp officer who was previously in police department, he told me that police and isi personnels got maximum benefits after doing css like earlier job promotion etc

He was in police department previously and after qualifying css his preference was to join the same department.he got earlier promotion within six month.but if someone is not interested in police or millitary and cantonement department and want to join other departments like custom or forigen service will he get any benefit?