The best way to know if your GMAT is competitive is to review the class profile on a given school's website. You can see the average GMAT score, and often a range of scores of those admitted. If you feel you are way off/low, then it's best to re-take if possible, and schools take the highest score. You can sometimes re-take quickly. You could also contact the school's admissions office and let them know a re-take is scheduled and see if there is any chance of adding that to your profile after you submit if it's very soon after; not standard practice in the top US schools but worth a shot and I'm less familiar with the Indian school's policies in that regard so always a good idea to ask if needed!
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