What do you mean "unlimited"? It's not unlimited. There's a data cap after 300GB of usage on the Rs. 1999 plan being offered.

I'm not a foreigner. I live in Lucknow, India and this is what my options are right now.

http://www.sikkanet.com/home-users/unshared-plans/

http://www.sikkanet.com/corporate-users/

http://www.techiit.com/airtel-broadband-tariff-plans-lucknow...

In the case of Airtel, "upto 16Mbps" means that maximum 4Mbps due to "technical restrictions."

You're lucky that you're getting that kind of a connection. Hyderabad, Bangalore, Delhi and Kolkata are probably the only cities in India where one can get that kind of a connection without trouble.