The Indian Civil Services are organised into two main sections. (i) All India Services and (ii) The Central Services. 

All India Services :
Indian Administrative Service (IAS)
Indian Police Service (IPS)
Indian Forest Service (IFtS)

Central Services -Groups A&B

Group A:
Indian Foreign Service (IFS)
Indian Railway Service 
Indian Postal Service
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.)
Indian Customs and Central Excise
Indian Ordinance Factories Service
Indian Defence Estates Service
Indian Revenue Service
Indian Information Service
Central Trade Services
Central Industrial Security Force

Group B: 
Central Secretariat Services (Section Officer Grade) 
Railway Board Secretariat Services (Section Officer Grade) 
Armed Forces Headquarters Civil Services (Assistant Civilian Staff Officer Grade) 
Customs Appraisers’ Services
The Delhi, Andaman and Nicobar Islands, Lakshadweep, Daman & Diu and Dadra & Nagar Haveli  Civil Services
The Delhi, Andaman and Nicobar Islands, Lakshadweep, Daman & Diu and Dadra & Nagar Haveli Police Services
Pondicherry Civil Services
State Civil Services

The categories of services to which candidates are selected through the SCS examination are as under:
(a) State Civil Services, Class-I (SCS)
(b) State Police Service, Class-I (SPS).
(c) Block Development Officer.
(d) Tehsildar/Talukadar/Asstt. Collector.
(e) Excise and Taxation Officer.
(f) Distt. Employment Officer.
(g) Distt. Treasury Officer.
(h) Distt Welfare Officer.
(i) Asstt Registrar Cooperative Societies.
(j) Distt. Food and Supplies Controller/Officer.
(k) Any other Class-I/Class-II service notified as per rules by the concerned State.