Hi uditgopalka,
While the most realistic CATs available are the 6 from GMAC, 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 that matches the parameters that you will face when you take the Official GMAT) - so you can use any NEW CATs from any of those sources next.
In addition, the process of taking (and reviewing) a CAT requires a significant amount of energy and effort - and takes time to 'recover' from. This is one of the reasons why you typically shouldn't take more than 1 CAT per week - and your last CAT should be taken about 1 week before Test Day. Since your Official Test Date is now less than 2 weeks away, you should NOT plan on taking too many additional CATs/mocks before then. While you should be fine taking 1-2 additional CATs, you probably shouldn't take any more than that.
GMAT assassins aren't born, they're made,
Rich