Bitcoin is a global currency not operated by Reserve Bank Of India.
It is a virtual currency of virtual world that is internet. No one cannot stop bitcoins circulation. For stopping bitcoin in India all internet services needs to get suspended first. If internet services continue than India will be loosing huge amount of their own national currency. Government of India knows that people had already invested in bitcoins and if it got banned people will seek for the foreign exchangers which will lead to money laundering.
If bitcoin banned in India than Government Of India will loose their taxable income too which they will be getting from the miners of bitcoins or exchangers which are operating in India like zebpay or unocoin.
In our country the problem is people are taking bitcoin or other cryptocurrencies like shares. It is not a share market, it is something different.
RBI never said that they are going to ban bitcoin or they are against the bitcoin they only notified that govt. wont be responsible for any loses if happens or bitcoin gets disappear from the world because they haven't made this currency as it is not physical it is virtual.
Even Government of India cannot openly say that bitcoin is legal because every one knows India is fighting against terrorism and if they say it’s legal than terror funding through bitcoin is tension for Govt.
Second reason no country wants to make another currency stand parallel to their own National currency.
Every country is planning to introduce there own cryptocurrecy to fight with Bitcoin.
Wait for the news from India about India's official cyptocurrency, that time every bitcoin holder in will get a chance to exchange it from India’s cryptocurrency.