Mechanical Engineering

Yes, you can study a PGDM course after Diploma in mechanical engineering. It is a viable choice for many who want to enter the field of management and secure a top job with some of the best companies. Eligibility to secure admission in a PGDM course is mentioned below:
To be eligible for admission to the PGDM programme, the participants must possess a Bachelors degree or equivalent, with a minimum of 50% aggregate marks or equivalent in any discipline, recognised by the Association of Indian Universities for admission to post-graduate programs. Regards.

You need to be specific about your selection of course, according to which you can select the universities and colleges of Canada.

Assuming you belong to general category, you really don't have much options. You won't get anything out of JOSSA, so I would suggest you to explore your other options such as other entrance exams, such as BITSAT VITEE, SRM to get a seat in decent private college. All the best.

It's simple. Just choose CS branch in any undergraduate programme like B.E/B.Tech etc. If you have completed your Diploma, then you can get the lateral entry in UG programme. It is not necessary to have same branch that you have choose in your Diploma.

Hello Asha,
Let me first say congratulations to you for deciding to pursue graduation in engineering after your diploma. But let me caution you. Supreme court of India had cancelled all engineering degrees obtained via distance education mode. You can seek lateral admission or can think of doing AMIE which is equivalent to engineering degree.

There are many good colleges in Pune, basically, the government colleges like College of Engineering, Pune etc.
Here is a link:
https://www.shiksha.com/b-tech/ranking/top-engineering-colleges-in-Pune/44-2-0-174-0

It depends on the college in which you are going to take admission. In private college, the fee is more as compared to a government college. In UPTU, the fess is about INR 96000 for private and 60-80K for the government college. In Punjab, the fee is about 85000 INR in both private and government colleges.