Large and bulky telephone directories have given way to the Online Telephone Directory, a service provided by the Bharat Sanchar Nigam Limited (BSNL). In Delhi and Mumbai this service is provided by Mahanagar Telephone Nigam Limited (MTNL). You can now search for the required phone number in a fast and effective manner.
The Government of India is providing you a very nice place where they have placed field for search of any telephone number of any state or metro city.
You will reach the following site
Just select the State or Metro City , and you will be taken to next window where you can either put name or telephone number
Additionally you can also search for ISD or STD code of any place and also contact numbers of Govt organisation