After lots of trial and error, online search I still could not figure out how to enable the BSNL 3G configuration. And as a last option I called up the BSNL customer care (1503 from your mobile. Press 2(For english), again 2 (for main menu) and then 9 for talking to a customer care executive). To my surprise someone answered the call at around 9.30 P.M., spoke good english and more importantly answered my query.
Step 1: Send a SMS to 58355 in the following format.
Step 2: You will receive 4 configuration messages which can be opened with a PIN no.
Step 3: PIN no is 1111
Step 4: Use the PIN, open the configuration message and save it. Do the same for all messages.
Thats all. Initially your phone will show 3G, and when you successfully configure it becomes 3.5G.
As mentioned in the previous post, the speed is really good and network coverage is quite good( It catches only in big cities/towns though. I tried in Hosur, Ambur and Vaniyambadi where the network went to 2.5 G and from Vellore to Chennai it became 3.5G again). Ofcourse it works in many places in Bengaluru/Bangalore.
So far so good.