B.Tech

Yes, you can as the basic criteria is BE/ B.Tech/ M.Sc or equivalent and GATE score should be above 300 or qualifying score, whichever is higher.

The job opportunities will depend on your specialization in MBA. If you have taken finance, then you could join investment banking or equity research area. In case you have taken marketing, then the field is wide open for you and join any industry in the sales domain.
However, keeping in mind your B.

Yes, you can do that. The career prospects are really good, if you do MBA from a reputed B-school in any stream.

Regular B.Tech is superior to AMIE because of its wider acceptance in job market in India and abroad.

You are eligible for B.Ed based on your Engineering degree. You are advised to appear in B.Ed entrance exams conducted by various states or universities.

Chances of getting an interview call is less. Write a good SOP for getting shortlisted.

Yes. Start preparing for GD and PI rounds at NITK. All the best.

No, you cannot pursue B.Tech in food technology after completing Diploma in mechanical engineering.

Different universities or institutes have their own formula for converting percentages to grade point score. Simple calculations are to divide percentage with 10 for a CGPA on the scale 1-10 or divide with 20 for a CGPA on the scale of 1 to 5 or divide with 25 for a CGPA on the scale of 1 to 4.