Hi Rushabhjinwala,
To start, a 590 is a strong initial CAT score (the average score on the Official GMAT hovers around 550 most years). That having been said, raising a 590 to the point that you can consistently score 700+ will likely require at least 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. With just 1.5 months though, there might be a limit to how much you can improve - so you might need to consider pushing back your planned Test Date.
1) What Schools are you planning to apply to?
2) What are the exact application deadlines that you are facing?
GMAT assassins aren't born, they're made,
Rich