Hi Ayushi7,
The scoring algorithm on the Official GMAT is far more complicated than most people realize. Since that algorithm is proprietary, no GMAT company has an exact match for it, thus CAT scores can vary a bit based on the 'biases' involved in their respective designs. The most realistic CATs available are the 6 from GMAC (the 2 free CATs, and each of the 2 that come with Exam Pack 1 and Exam Pack 2), but retaking a CAT that you've already taken is NOT a realistic way to assess your skills - since you will likely see some 'repeat' questions that you have already faced. Unfortunately, seeing even a couple of repeats can 'throw off' the Scoring Algorithm and impact your pacing, energy levels, fatigue, etc. (meaning that they would likely all appear to be better than they actually are). Thankfully, the CATs from Kaplan,
MGMAT and Veritas are all 'close enough' to the real thing that they will provide you with a relatively realistic score assessment (assuming that you correctly take the CAT in a realistic fashion).
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, most of your CAT score results show that you essentially performed the same each time (about 680 +/- a few points); the 760 is a significant 'outlier' (and as such, we cannot assume that it is an accurate reflection of you current ability level). You handle certain aspects of the GMAT consistently well, but you also make certain consistent mistakes. Assuming that you took each of these CATs in a realistic fashion that matches-up with how you will take the Official GMAT, then you're performing at a fairly consistent level right now.
A CAT is really a 'measuring device' - when used correctly, it will give you a realistic score and help define your strengths and weaknesses, but it will NOT help you to fix any of those weaknesses. To raise your scores, you have to learn the necessary Tactics and put in the proper practice and repetitions. The CAT will show you whether your studies are helping you to improve or not. As such, you really shouldn't take more than 1 FULL CAT per week going forward.
GMAT assassins aren't born, they're made,
Rich