Hi raizfaia,
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:
1) How many hours do you typically study each week?
2) 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)?
3) When are you planning to apply to Business School and what Schools are you planning to apply to?
Statistically-speaking, raising a 600 to the point that you can consistently score 680+ will likely require at least another 2 months of consistent, guided study - and you'll have to make significant improvements to how you handle BOTH the Quant and Verbal sections. Thankfully, the GMAT is a consistent, predictable Exam, so you CAN train to score at a higher level - but you might want to consider pushing back your Test Date.
GMAT assassins aren't born, they're made,
Rich