Canada

I think you are asking which regions in Canada have the most digital marketing jobs, with the widest variety of business models. In that case, I think Toronto has to be tops. It has one of the most diverse array of industries in the world, being the 2nd largest cluster of companies in North America in about a dozen major sectors (telecom, banking, retail, pharma, tech, mobile, media, advertising, etc.).
All the best.

The 3 main reasons could be submission of incorrect information, your academics and finances. From 2009 onwards Canadian system is ok with dual intent, so intent of staying back in Canada is no longer that big an issue. However what it means is that you need to submit correct information, have a strong study plan and sufficient finances for the duration of your course

SPP program is available for mostly colleges (which offer applied degree's, diploma's and certificates) and a very small number of universities. If you want to do bachelors in engineering, you can do it directly from an SPP institution or non SPP institution. You haven't mentioned which level you want to study in Canada under SPP and for which level you are asking for your chances. It's difficult to give answers as you may get information which is not applicable to your situation.

Your question is not clear. Are you asking about Masters in Canada after you have done engineering here in India?

You can do anything, as long as you have the marks and meet with any special requirements. Most institutions offer anything between 40-200+ courses. It's up to you to choose from the options. You haven't mentioned what level you want to study - UG or PG.

No, a few require 6.5 but you should be able to get through as most of the colleges ask for 6 band.

Yes, you can. As long as you have fulfilled the conditions that caused the earlier refusal.

Yes, you can pursue B.Sc in nursing from Canada.

Dentistry in Canada is a second degree which means that you can't study of after doing your 12th here. You have to do your Bachelors in Canada (preferably in biological or medical stream), then clear the competitive exam, interview, etc.