Hi arjun1991,
I'm sorry to hear that Test Day didn't go as well as hoped. It's likely that your concerns about endurance/fatigue were correct and that you probably needed more study time to properly train for the Official GMAT.
The process of applying to (and ultimately attending) Business School requires a considerable amount of time, money and energy. As such, you should really make sure that the degree that is offered by a particular Program is one that matches YOUR wants/needs. Instead of focusing on "which School will likely accept me", you should think about what you want out of the MBA, then find Schools that match up.
Here are some things to think about:
1) Is there a particular company that you want to work for or industry that you want to work in? Certain degrees are more appropriate than others if you have a specific career goal.
2) What do you want your MBA to do for you?
3) Do you want to go to School full-time or part-time?
4) Are you willing to relocate? Are you comfortable with working through a program that is primarily online?
Etc.
Once you've determined what type of Program you want to attend (as well as the other variables involved), then you can start to research and narrow down the possibilities. You might also want to retake the GMAT.
GMAT assassins aren't born, they're made,
Rich