Do I need to send in my HSC grades for a Masters in US/UK/Canada ?
The HSC board in India is the equivalent of the 11th and 12th grade internationally. For Masters programs you need to submit your undergrad GPA and not your high school transcripts. So after your HSC if you are pursuing B.com, BMS, B.A, BSC, BAF - those are the grades that matter.
Additionally, some US universities require 4 years of undergrad education - since in India we complete it in 3 years you could do either of the two things
Drop an email to the admissions office with your transcript and explain how we have only 3 years of undergrad education here and if this would be ok for your application.
If you do not want to take a risk, it would be a good idea to do an MCom by correspondence and since this is not that intensive, take up an internship or full time job opportunity to further supplement your application/resume.
Hope this helps