It really takes a long time Vikram. The official time mentioned by BBMP itself is around 40 working days. You will have to followup a zillion times to get any update. Might have to file a RTI as well to know the status. So be prepared for a long drawn battle. You should also be very careful of the touts/brokers that claim to get it done quicker for a fee. There are numerous instances in Bangalore when the broker takes the money and runs away without getting your work done. I will strongly recommend that you hire the service of a lawyer to get this done.