Hi there,
The good news:
The short answer? No, don't retake the GMAT. Congratulations on moving from a 650 to a 720 but the effort required to improve that even slightly is going to be significant and probably not worth it. Your quant isn't THAT low - it isn't on par with the average for your applicant pool (Indian male) but it isn't terrible. Overall, a 720 is good enough for you!
The Less Than Good News:
The rest of your profile is a little more on the average side. You have some interesting components (Green Peace, learning jazz) but that isn't going to be nearly enough to carry you. A big question you need to answer is what did you DO for your local IT company? If you had some amazing, above average work experiences there, that will help. However, your undergraduate GPA is average and not a differentiator. Additionally, your involvement in undergrad is lacking and while some of that may be explained away in an optional essay regarding your family circumstance, at the end of the day donating blood isn't an activity unfortunately.
At the moment, I would say your chances aren't great. Now, my opinion may change when you tell me more about your work experiences but if I were you I would look to strengthen your profile in the next few years in two main areas:
Professionally: look for projects or opportunities where you can stretch yourself, manage ambiguity, and drive impact. It's all about impact. If you wrote status reports for three years, it isn't going to get you very far.
Extracurricularly: Get involved in activities that drive impact and speak to your passions. But look for areas where you can augment your professional experiences for leadership experience and other key themes you're going to need to hammer into your application. Taking what you wrote at face value, I feel you would have a very difficult time writing a compelling set of essays to stand out from the pack.
If you let me know some more information about your work experiences - I would love to help!
I hope that wasn't too negative sounding - I think you're asking the right questions and setting yourself up for a successful run but in a year or two, maybe not this one.
Bhavik