RBI ban cryptocurrency trading through banks but they also argued that they are not against block chain and digital technology, they support it and they ban cryptocurrency because it has many harmful effects for now on Indian economy like corruption, hacking and many more
So we can't say it is a permanent ban on crypto in India, we can hope if some regulations will come in future or if government will find some useful cases of cryptocurrencies then there may be chances of crypto to be legal in India

If we talk about exchanges then there are some exchanges doing well with P2P trading
For zebpay, they did a very good job in Indian crypto world but I can't comment on the future plans of zebpay unless I have always positive hope regarding crypto world