Hi Neha,
I'm sorry to hear that Test Day didn't go as well as hoped. Based on some of the things that you described (over the last several days) in this thread...
https://gmatclub.com/forum/gmat-books-2 ... l#p1893205...You were getting a significant number of questions wrong because of silly/little mistakes - so I have to assume that that's what happened on Test Day too. GMAC has publicly stated that the Official Score that you earn on Test Day is within +/- 30 points of actual ability. Assuming a similar 'swing' in how your CATs function, your various score results point to a general ability level in the low-600s (with a 'low end' of about 590 and a 'high end' of about 640).
Given your score goal and first-choice School, a retest will be a 'must.' Unfortunately, it's going to take some significant time to raise this 590 up to a 700 - likely at least another 2 months of consistent, guided study. There's no reason to give up on any of this though; an MBA is almost certainly worth all the effort that you'll have to put in to achieve it - and this is just one 'stumbling block' that you CAN train to get past.
1) What are the Round 1 and Round 2 application deadlines for ISB?
2) Are there any other Schools that interest you?
GMAT assassins aren't born, they're made,
Rich