As far as I know,they're allowed to go back to India whenever they want. However, they are then in violation of their contract. I don't know what the details of that contract are. I have heard 2 conflicting stories:
They get paid room, board and $50/month while here and either their families get another $150 per month while they live her OR $150 per month is deposited in a bank account to be paid at the end of their tour as a guarantee of good behavior. either one might be true, or it might be that the payment plan started out one way, and ended up the other (or even: some pandits have one deal currently, while others have a different deal). There are so many accusations about Girish Varma's misbehavior back in India, it is impossible to be sure what is what without actually being the person in charge of the finances back in India. L
