Now thats depends upon the facilities like Accommodation , Mess , etc you got ..
This is my not much precise calculation ..
Accommodation - 2000 ( A good PG House, Or 2BHK flat shared by at least 5 members )
Food - (one time mess, well go around Rs 800 )
Transport - (If city bus is concerned, 600 monthly pass can take you anywhere in the city ).
Others stuff like hoteling, movies, GF
, expense that's totally depends upon you !
So final figure , you decide !