Central services are classified into two groups :

GROUP A

01.Indian Foreign Service (IFS)
02.Indian Railway Service
03.Indian Postal Service
04.Accounts and Auditing Services (including
     The Indian Audit and Accounts Service,
     The Indian Civil Accounts Service,
     The Indian Defence Accounts Service,
     The Indian Revenue Service.)
05.Indian Customs and Central Excise
06.Indian Ordinance Factories Service
07.Indian Defence Estates Service
08.Indian Revenue Service
09.Indian Information Service
10.Central Trade Services
11.Central Industrial Security Force
12.Indian Post & Telecommunication Accounts & Finance Service
13.Railway Protection Force (RPF)
14.Indian Railway Personnel Service (IRPS)
15.Indian Railway Accounts Service (IRAS)
16.Indian Railway Traffic Service (IRTS)


GROUP B

01.Central Secretariat Services
     (Section Officer Grade)
02.Railway Board Secretariat Services
     (Section Officer Grade)
03.Armed Forces Headquarters Civil Services
    (Assistant Civilian Staff Officer Grade)
04.Customs Appraisers’ Services
05.The Delhi, Andaman and Nicobar Islands,
      Lakshadweep, Daman & Diu and
      Dadra & Nagar Haveli Civil Services
06.The Delhi, Andaman and Nicobar Islands,
      Lakshadweep, Daman & Diu and
      Dadra & Nagar Haveli Police Services
07.Pondicherry Civil Services
08.State Civil Services