Canada

Yes, Seneca is one of the more popular colleges among Indian students. However, please mention if you are talking about the graduate certificate course or Diploma course.

Almost all courses except mathematics and accountancy. Please mention your academic details and if you are looking for an undergraduate or a post-graduate course to get a more precise answer.

Scholarships for universities abroad are a domain of the college itself. So if you are applying to a certain college, the admission officer will automatically shortlist you for scholarship if your profile is eligible. In most cases, you don't have to apply separately for scholarships.
You need to get in touch with the university or college of your choice. Ask them about the eligibility criteria for scholarships are they are different for each institute.

Please mention which course and colleges are you interested in applying to.

Province does not play a vital role in studies, so you have to choose a university as per your profile, and the reputation of the university, but southern Canada is a little bit better for core engineering.

To get an exact answer, please clarify your question.

Since you have already done MBA, just check the skill shortage list for Canada and see if you can apply for jobs. If not then doing a P.Hd is another option or may be a Diploma to get a job and then PR.

Any university in Canada would require 80-85% at least for science courses. Better percentage along with a good profile in co-curricular will help you.