Canada

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.

You can give any one. Both are accepted. But if you are applying to an SPP college then IELTS is preferred.

Everything is possible but that does not necessarily mean that it is probable. That's the short answer. Long answer, yes, it is possible as long as you meet the required criteria for PR. However, chances are that you will not meet their criteria and so it may not be possible for you. For the criteria details log into IRCC/ CIC website:
http://www.cic.gc.ca/english/immigrate/INDEX.PHP

Hi Harsh, every college and program have different requirements. It is difficult to say which course you can pursue or which university you will be admitted. 12 is a big number, apart from this you must check your academic grade requirement and also IELTS/TOEFL score requirement. Also which course you want to study is your choice and decision. Whatever you study must be relevant to your education background.

Hi Robin,
Some of the best are Western University, University of British Columbia, University of Toronto, Queen's University, University of Manitoba and University of Guelph to name a few.