Good luck resolving any latency issues with BSNL. I've tried for 2 years and gave up.
All they care about is :
1) Is internet working?
2) Is your line clear?
3) Are you able to hear the other guy talking on the phone?
The major problem here is communication. Only the folks at NOC (Bangalore/and one more city) can even understand issues with latency. Exchange folks are trained to keep line working and clear. They can't do anything else. Good luck talking to NOC directly (my connection is from an ex-BSNL employee, I've gone to great lengths in explaining my problem in person to an NOC official and yet they couldn't do a thing).
..
P.S, stop posting this on other threads, I know you're frustrated (I being an online gamer, can totally understand the importance of latency in your problem) but posting it everywhere with mean words will only get you in trouble with the admin here.
Just my two cents. Either live with BSNL or change to another provider. If you don't have another provider, then either move out or pray. Only god can help you out.