Hello, here I am providing you the details of the Area of Kolkata Municipal Corporation as under:

Area of Jurisdiction
Kolkata Postal District however extends right up to Barrackpur in the North, Barasat in the East, up to Baruipur in South-East and Joka in South and up to Batanagar in South-West. The Postal code in this entire area starts with 700, indicating Postal Sorting District of Kolkata.
Thus Kolkata Postal area is much bigger than the area of KMC, Kolkata Police or Kolkata District. In general term, people identify a locality with its Postal address.
Postal address of people residing in the delivery jurisdiction of any of the 160 Delivery Post offices of Kolkata will be having PIN Code no. from 700001 (Kolkata-1) to 700160 (Kolkata-160).

Area:
Old Kolkata : Sutanuti -
Chitpur, Baghbazar, Sobhabazar & Hatkhola.
Kolkata - Dharmatala, Bowbazar, Simla, Janbazar.
Gobindapur - Hastings, Maidan & Bhowanipur

New Kolkata :
North - Sinthi, Cossipore & Gughudanga
South - Tollygunge, Khidderpore & Behala
East - Salt Lake , Beliaghata & Topsia.
West - Hooghly river.

Greater Kolkata :
Baruipur to Bansberia & Kalyani to Budge Budge.

Services
Water purification and supply
Sewage treatment and disposal
Garbage disposal and street cleanliness
Solid waste management
Building and maintenance of roads, streets and flyovers.
Street lighting
Maintenance of parks and open spaces
Cemeteries and Crematoriums
Registering of births and deaths
Conservation of heritage sites
Disease control, including immunization
Public municipal schools etc.