Party places would be better to know about as I am a party animal.
Kolkata has the best nightlife compared to every other metro city in India. You can go to Dublin, The Park, Aqua, Lytton Hotel and Someplace else Pub. Tantra is one of the most happening luxury bar and nightclub in Kolkata. You can not find a place more busy than this in whole city at night. Most nightclubs are apt for every type of person and they have music, disco, hip hop, trance, Hindi pop and remixed Bhangra which suits all type of people.