Hi Fareeha,
A 600 is a good initial CAT score (the Average Score on the Official GMAT hovers around 550 most years). Many GMATers spend 3 months (or more) of consistent study time before they hit their 'peak' scores, so giving yourself 4 months of potential study time is a smart choice. Whether that's enough time for you to get to the point that you can consistently score 750+ or not is not a question that anyone can answer for certain (as that Score require that you hone a variety of Quant and Verbal skills). Thankfully, the GMAT is a consistent, predictable Exam, so you CAN train to score at a higher level.
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 your timeline and your goals:
1) What study materials do you currently have access to?
2) Going forward, how many hours do you think you can consistently study each week?
3) 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
Contact Rich at: Rich.C@empowergmat.com