Add to this that RBI is intentionally trying to keep the dollar to Rs ratio at about 60, if they choose to de regulate the dollar will fall to half I.e 30. You can find articles almost every month where RBI buys dollars from indian markets and sells them at a lower price.
Logic of keeping it at 60 is to encourage investment from Americans at this point in time. If RBI chooses to deregulate GDP in dollar terms will increase tremendously. Downside of This would be we are not richer by any means and investments will stop flowing. Only on paper we will be richer. Upside is we might get some bragging rights which are no use.