Hi vatstarun,
Since Business Schools don't care if you retake the GMAT, taking the Test for a third time would not be a problem.
You're talking in general terms right now, so I would suggest that you research the specific Schools that fit what you're looking for. In that way, you can learn more about application deadlines, class profiles, average GMAT scores, costs, etc. With that information, you'll be better able to decide whether to retake the GMAT or not.
In general though, if you're planning to apply to only Top-Tier programs, the average GMAT scores for those Schools are likely going to be much higher than your recent GMAT score. As such, you're probably going to need to retake the GMAT. To make the most out of your available study time, you might want to consider investing in a GMAT Course of some type.
GMAT assassins aren't born, they're made,
Rich