Hi sachin0890,
The scoring algorithm on the Official GMAT is far more complicated than most people realize. It takes into account a number of different factors - more than just the number of correct and incorrect answers. As such, you shouldn't be spending time trying to figure it all out. You'd be better served working on building up your skills. Based on your question, it sounds like you've put in some significant study time already.
Studies:
1) How long have you studied?
2) What materials have you used?
3) How have you scored on each of your CATs (including the Quant and Verbal Scaled Scores)?
Goals:
4) What is your goal score?
5) When are you planning to take the GMAT?
6) When are you planning to apply to Business School?
7) What Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich