Hi Reyansh,
Since it sounds as if you have done some significant studying already, then you really MUST take a FULL-LENGTH CAT (including the Essay and IR sections) sometime soon. That initial diagnostic CAT is important - it helps to define your strengths and weaknesses and gives you a basis for comparison as you continue to study. Many Test Takers are not happy with that first CAT result, but that's not a big deal - the extra months of available study time are there so that you can IMPROVE on your initial practice result.
Beyond that, it would help if you could provide a bit more information on your timeline and goals:
1) When are you planning to take the GMAT?
2) When are you planning to apply to Business School?
3) What Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich