Hi sam12rawat,
GMAC has publicly stated that the Official Score that you earn on Test Day is within +/- 30 points of actual ability. Assuming a similar 'swing' in how your CATs function, your 3 CAT score results show that you essentially performed the same each time (about 530 +/- a few points). You handle certain aspects of the GMAT consistently well, but you also make certain consistent mistakes.
Before I can offer you any additional advice for your studies, it would help if you could provide a bit more information on how you've been studying and your goals:
1) What type of study routine have you been following? How many hours do you typically study each week?
2) What study materials have you used so far?
3) On what dates (or approximate dates) did you take EACH of your CATs/mocks and how did you score on EACH (including the Quant and Verbal Scaled Scores for EACH)?
4) What Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich