Where can i find a blackmarket in bangalore?

I need to buy an iPhone 4 or 4s. Can anyone suggest me a blackmarket?

What do you mean by black market? You don't have to depend on any blackmarket, there are so many techies of bangalore who visit US, and during their return bring i phones for personal use and also to sell in local market to make some money

people advertise (openly) in various sites about the sale of i phones,
or you may go to SP road, there are so many shops,
or try craiglist bangalore
finally you may try national market in gandhinagar near majestic

apple india has an office in 19 Floor, Concorde Tower C UB City No 24 Vittal Mallya Road., you may contact them

National Market at Majestic is the best.
This markets are close to each other. You can get all kinds of cheap electronics goods like watches, phones and camera, etc.

National market in gandhi nagar. Its near to tribhuvan theatre.