Hi Puneet Gupta,
To start, a 570 is a solid initial CAT Score (the average score on the Official GMAT hovers around 540-550 most years). Before I can offer you the specific advice that you’re looking for, it would help if you could provide a bit more information on how you've been studying and your goals:
Studies:
1) How long have you studied?
2) Have you used any other study materials besides the ones noted?
Goals:
3) What is your goal score?
4) When are you planning to take the GMAT?
5) When are you planning to apply to Business School?
6) What Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich