i personally have used these three they really works good . my review >
Zebpay: Higher bitcoin prices,secure,but transaction fees is 0.0002 BTC for BTC to BTC transaction. Works fine if you like to purchase some amount of BTC.
Unocoin : You can use it similar to zebpay. You can purchase directly from site.
coinsecure: Lesser rates compared to other exchanges.Good support and service. Similar to unocoin.