You really do not need any regulation to stifle these sort of pyramid schemes ,Zebpay and unocoin being the exchanges relating to bitcoin they have to create awareness to the users in India and if you are able to give that to the new people who are coming into bitcoin then you will be able to defeat all these things.
Why would anyone put a barrier ahead of their probable customers.
Exchanges are earning from it, they would not make a war footing effort to stop scammers.
The users need to be aware of such scam and invest wisely.