Dear Mr. Salman,
That's a good question. Well.... you have two options to experience the upcoming Tata DoCoMo (GSM) services. The first is to buy a new SIM card as soon as they are available in Hyderabad, but you'll get a new mobile number. The second option is to wait until the Mobile Number Portability (MNP) is launched and then switch to Tata DoCoMo, this way you can retain your existing number and still switch the carrier to Tata DoCoMo. As per your question, the second option is more appropriate for you.
MNP is due for launch in Andhra Pradesh probably by October if everything goes as planned.
Here is a news article about MNP: http://www.livemint.com/2009/06/03132421/E...-Number-Po.html
Note: Tata Indicom has nothing to do with Tata DoCoMo, they are two different brands running on two independent network hardware equipments.
Hope this helps you!
Hey Bhargav,
Thanks for the heads up...I thought this was a partnership
It's sad to hear that I will have to wait till October for the MNP.