How safe is Zebpay? How can I trade in Bitcoin in India?

Zebpay is pretty safe but I would not suggest Zebpay because the difference between buying price and selling price in Zebpay is usually high. It depicts market order.

Instead you can try http://Koinex.in where you can see various buy and sell orders of end users like you and the difference between buy and sell order is very minimal. It depicts Limit Order.