Hi Kaushik,
To properly plan out your study routine, It's important to define your goals and general timeline.
1) What is your goal score?
2) When are you planning to apply to Business School?
3) Do you know which Schools you'll be applying to?
With a Test Date in the latter part of September, you have about 2 months to study, which might not be enough for you to achieve your goals (considering what you've described about your studies so far). Your first FULL-LENGTH CAT score will provide some valuable information about your strengths and weaknesses and will provide a way to measure your progress going forward.
GMAT assassins aren't born, they're made,
Rich