Hi Pramod,
For free math practice and help, I recommend that you set up an account at Khan Academy (
www.khanacademy.org). The site is completely free and makes the learning a bit more fun and 'game-like' (as opposed to the dry academic approach taken by most books). While the site is vast, you should limit your studies to basic Arithmetic, Algebra and Geometry. After spending a little time re-building those skills, you can continue your GMAT studies.
1) How long have you been studying?
2) What resources have you been using?
3) What is your goal score?
4) When are you planning to take the GMAT?
GMAT assassins aren't born, they're made,
Rich