Hi Gaurav,
A score goal of 780 is impractical for a couple of reasons. First, over 99% of Test Takers will never score at that level, regardless of the number of times that they take the GMAT. Second, NO Business School requires a GMAT score that high. This is all meant to say that while you certainly need a competitive GMAT score, you might want to be a bit less extreme about your score goal. All of that having been said, I don't have any suggestions as to which Schools/Programs you should apply to. My advice would be to try to define what exactly you want your MBA to do for you - then research the Schools that match what you're looking for.
Based on what you've described, I'd certainly be interested in hearing how you do on your first CAT, so you should plan to post back here once you've completed it.
GMAT assassins aren't born, they're made,
Rich