Yes, 650 is 84th percentile, a good score. The schools do not require a 700+. The top schools do have a median score in the low 700s, but median means half of their admitted students have scores below that level. I say this not to discourage you from taking the test again - if you want to, you should - but to let you know that this is not, by any means, a disaster. I know people who have gotten into top 10 schools (recently) with low 600 scores.

A GMAT score will never get you into b-school, and a 650 or higher will never get you rejected. (That doesn't mean you'll get in - it just means that, if they reject you, it will be for some combination of reasons and the GMAT will not be the major factor in the decision.)

Our courses run for 9 weeks, so you don't have time to complete a course by 15 Sep. You could do some private tutoring, though that is significantly more expensive. You can also buy access to any combination of our materials (hard or online) and study on your own.

Take a practice test ASAP on which you have the ability to generate detailed, question-by-question analyses of your results (our tests generate these reports for you). Identify your weaknesses relative to question types, content areas, pacing, and difficulty levels, and work from there.