Here in the US (and maybe in some other places) sometimes the cellular providers have deals to "give" you the iPhone 7 if you agree to service with them for a period of time. My carrier for example gave me an iPhone 7 for free, for 2 years. I make 30 dollar payments, but they credit my account 30 dollars to offset the payment. I'm locked in because I agree to make the payments. I'm pretty sure no such plans exist in India, or so I have heard from friends who live there. So your best bet is contests. Please note many contests may be limited to North America.