According to an article yesterday in the Tribune, the India Department of Telecom has just issued some new guidelines on foreign nationals getting SIM cards in India. Now you can’t get a card that is valid beyond the validity of your visa. In the case of people who are on Tourist Visas, the maximum validity is only 3 months, even if your visa is valid for longer.
That means that if you have to leave the country to get a new visa, you have to get a new SIM card (and a new phone number) when you come back in. You have to not only provide a copy of your passport and visa, but you also have to give a local reference. The address proof can be that of a tour operator or even a hotel where one is staying. There is, of course, a whole form to fill out. Indian red tape is never-ending.
Apparently, there have been many instances of numbers getting passed on from visitors leaving the country and misused in some way. I doubt this will help much, though, as Indians, being the friendly and helpful people that they are, are usually happy to help out with getting around regulations like this.