Canada

Hi Himanshu,
A first class is recommended. To get into a good university a score of 75% and above is required. Admission cut-offs varies with universities, you must check separately. Do remember that you must have received the admission offer from a college or university before you can apply for the student visa.

Only you can answer this as your choice of course completely depends on your academic and work history plus your areas of interest.
Which course would you like to pursue? What is your academic profile and work history?

Any course, you will pursue will have good job prospects, as it all depends on your capabilities to be a great student and employee. If you manage to score well in your course, and get an internship with a reputed company, you will not have any problem finding a good job.

Diploma courses are more technical in nature and degree courses are more theoretical. The job opportunities depend on your skills and subject knowledge. If you are good at your course and score well, then you should have no problem getting a good job with either course.

What are the areas of your interest? As your course choice will depend on that.

Hi Gagan,
After completing the Diploma, you have the option to complete Bachelor of dental sciences at UBC and a Bachelor of health sciences from TRU. To start looking for jobs, you must acquire a license first, to be eligible for registration and licensure with the College of Dental Hygienists of British Columbia.
Graduates must pass the national dental hygiene certification examination. It is better, if you obtain a Bachelor's degree for better job prospects and later think of a PG level qualification. Please note that programs intake is under review. So, contact the college directly before applying.

There are many colleges in Ontario that provide tourism courses.
You can check the below mentioned link:
http://www.ontariocolleges.ca/SearchResults/CULINARY-HOSPITALITY-RECREATION-TOURISM-TOURISM-TRAVEL/_/N-lqh5

Can you mention your area of interest? There are no generic best courses, it all depends on your preference and choice.

Can you mention the Diploma level? Do you mean undergraduate Diploma or post graduate Diploma?
You need to have at least 60% to pursue a Diploma in Canada. Plus you need to have scored 6 overall bands for undergraduate course and 6.5 overall bands for post-graduate courses.

Can you mention the name of the undergraduate degree and the exact specialization?