Hi ravisinghal,
You haven't provided much information in this post, so it's tough to offer any advice. If you can answer a few questions though, then I'll be happy to advise:
1) What were the Quant and Verbal Scaled Scores on this CAT?
2) How long have you studied so far?
3) What resources have you used?
4) When are you planning to apply to Business School?
Thankfully, the GMAT is a predictable, standardized Test, so you CAN train to score at a higher level. Using this score a a gauge though, it's not likely that you'll be able to improve 140+ points in 3 weeks. As such, you'll likely have to push back your Test Date.
GMAT assassins aren't born, they're made,
Rich