"bhajan" is a slang for porn movie/video in 'IIT' lingo (the set of slangs used in the Indian Institutes of Technology). Its derived from the Hindi word 'bhajan' meaning a devotional song offered in prayer.
A: Dude I've seen this awesome physics textbook and I have to jerk off.
B: No problem, dude. I have just the right bhajans for you.