Sounds very solid, I like that you have extracurriculars and also a social impact dimension to your profile. Well rounded and *unrepeatable* contribution is the name of the game for you.
I did notice that you would be spending three months abroad in your original post, but my concern is that it will appear to the Adcom that you are checking boxes. Then again you have some time before applying. Would appear better should you integrate that aspect into overall profile which seems you are doing in your work. To answer your question, the NGO in my opinion. It will go a longer way than doing a one-year master program in finance. I just see that as a better strategy for separating you from other Indians, especially if it showcases people management and verbal communication skills. Something that would give you additional perspective that you could contribute in the classroom.
As for your grades, your GMAT score should allay most of their concerns, if you can write a convincing essay on why your grades were low. If you want to cover all your bases I would recommend that you check out the HBS Strategic Management certificate program.
Https://www.extension.harvard.edu/acade ... ertificate. One of my Indian IT clients with a 3.0 GPA got decent grades in that program, along with some good teamwork stories, which I believe helped him get into Stern. He had zero extracurricular, zero community service and a 730 GMAT. If If I do say myself we did a pretty great job with his letters, essays, and resume. He also got into Ross.
So Stern should be no problem, and I think and/or Cornell would be a backup school for you.
One other note, I think the European schools would salivate at your GMAT score. If you plan to do an internship, make sure to go for 2 year ar LBS and J-term intake at INSEAD.
Do get in touch with me if you'd like to talk about it further.
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