Hi aryanpawar,
I'd like to know a bit about your timeline and plans:
1) When are you planning to take the GMAT?
2) When are you planning to apply to Business School?
3) What is your goal score?
4) Have you done any studying at all so far?
To help you plan out your timeline, you should know that most Test Takers spend 3 months (or more) on their studies; during that time, it's common to spend 10-15 hours per week (or more) on the process. The GMAT is a predictable, standardized Test, so you can CAN train to score at a high level. You just have to be ready to put in the time and effort and you have to make sure that you have the proper resources to help you succeed.
GMAT assassins aren't born, they're made,
Rich