Distance/Correspondence

Yes, you are eligible. But you must score 50% marks in your graduation.

For correspondence MBA, you should go for a govt. university. IGNOU is the best option.

For managerial skills and management skills if you are looking for please take on MBA which will really help you. If you want to improve your technical skills then Diploma in Mechanical.

Dear Suman,
Not just in India, but in the entire world, you can never do engineering and medical through distance mode. So don't ask for B.Tech college in distance mode in Kolkata as you will not find and even if any college offers B.Tech in correspondence, means they are violating the rules of AICTE. Go and complaint them. So, go for regular B.Tech program.
Ask any query at anytime.
Good day.

You can do this Diploma course in New Zealand.
After one year study, you will get one year work search visa. In getting a job, you will get 2 year work visa and you can apply for PR.