Hey dude,
Good to hear from you.
Overall your profile seems like it is very strong and you have good numbers. It's not "necessary" to redo your GMAT at this point, but that doesn't mean that if you can't get higher, it won't help, especially as an Indian candidate. (Have a look at this article here, which might help you sort things out:
https://admissionado.com/mba/to-retake-o ... n=mba_blog)
That having been said, even with your great leadership and volunteer work, the school list you have is a touch tough. My suggestion would be spreading out your application more over the Top 20 schools. This should give you better hcances of getting in.
Finally, I should mention, that for you to make a successful application, may require you to "reinvent" how you think about yourself, and how you present your profile. Now, I feel your profile is very strong, but how you present it, is still too much "Tech-focused" and skill-focused" whereas to make a strong application it needs to be more MBA-focused and achievement-focused.
What else can I say? You have your GMAT, so time to get started on the rest!!!!
Best,
Jon