Thanks for sharing your profile:
1. How is my overall profile for above mentioned schools as well as for Top-20 B-Schools in US?
I think you have a good profile for top 20, good GMAT, track record of career progression, your challenge will be your competitive applicant pool
2. Would my limited international exposure and no community service be a concern? How can I compensate for this in my applications.
It won't help you, especially the lack of community service, you will have to tout the volunteer/ECs you have had as well as make sure the other areas of your profile make-up for this gap
3. Based on my profile, which Top-20 B-Schools may provide me decent amount of scholarships?
When looking at scholarships, your profile has to look premium in comparison to other candidates, so basically in comparison to the avg GMAT, GPA, work experience you should be in the top category at your target schools. So I would look at the bottom end of the top 20 for schools that fit that for you given your career goals