Hi NikitaVChoudhary,
Probability is a rather rare subject in the Quant section (you will likely see just one Probability question, although you might see more than one if you're doing really in that section AND the Randomizer gives you some additional tougher questions in that area - as opposed to tougher questions in other categories). As such, you should make sure that you're performing really well on the larger point categories before you worry too much about Probability.
In another post, you noted that your Official Exam is about 2 weeks from now. While you might be tempted to try to do a lot of studying during these last 2 weeks before Test Day, you should NOT be doing any "cramming" (as that type of approach rarely leads to great results with Exams such as the GMAT - and you'll greatly increase your chances of 'burning out' before Test Day, which is something that we want to avoid).
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:
Studies:
1) How long have you studied? How many hours do you typically study each week?
2) What study materials have you used so far?
3) On what 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)?
Goals:
4) What is your overall goal score?
5) When are you planning to apply to Business School and what Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich