Hi meghakamath234,
You're ultimately asking Admissions questions, so you would likely find it beneficial to speak with an Admissions Expert about your overall profile. There's a Forum full of them here:
ask-admission-consultants-124/Academically-speaking, a 510 is a below-average GMAT Score (the average on the Official GMAT hovers around 540-550 most years), so I would suspect that you'll want to retake the GMAT. Before I can offer you any advice in that regard, it would help if you could provide a bit more information on how you've been studying and your goals:
Studies:
1) What materials have you used?
2) How have you scored on each of your CATs (including the Quant and Verbal Scaled Scores)?
Goals:
3) What is your goal score?
4) When are you planning to apply to School?
GMAT assassins aren't born, they're made,
Rich