in india there are many exchange service.but normally people are using localbitcoin. but there are 1% chance of scam because of if seller don't release btc.so its better to buy on indian exchange like zebpay,coinsecure,BTCXIndia
but mostly i use zebpay because of easy to use.its give you btc in lowest price.
Even if seller does not release BTC, you just have to click the dispute button and then notify the LB support team that you have made payment and seller is not releasing BTC. They will check and if you have really made payment to right account mentioned by buyer they will release the BTC.