Canada

No, you can't. You need to do 2 years course to get a 3-year work permit.

It is very difficult to get into universities with that score. You can look into colleges though.

Few things that you can do are:
Keep your GPA good, publish some research papers, get good scores in GRE and IELTS/TOEFL. Then apply for the programme and wait for admission. Do let me know if you have further query as I got an admission into McGill.

Depends on your certain factors but the tuition cost is somewhere around 10 Lacs for a year and living cost is around 500-600 CAD. Total will come around 25-30 Lacs for 2 years.

Western University
York University of Saskatchewan
Saint Mary's University
St. Francis Xavier University
The Mcmaster University of Ottawa.

Canada does not offer graduation degree in medicine. However, you can get a postgraduate course in Canada. Contrary, Australia offers MD cum MBBS courses so you can check online about Australian medical universities.

For getting admission in Canada or New Zealand, there are different procedures to study MBA. In Canada, you have to give GRE or TOEFL, you should score a suitable score in this exam and for MBA, you have to complete your Bachelor's degree or other equivalent degrees that should be of 4 years and if

In order to do nursing, you should have PCB in your class 12 as subject. As nursing is completely belongs to medical field, hence, you can't pursue nursing after doing B.Com.

Yes, you can. But, the maximum universities minimum IELTS acceptance score is 6.5.