M.Tech Eligibility

Yes, you are eligible you don't worry about it. You have a B.Tech degree so you can do easily this hence start preparing for GATE.

Yes, it is easy to get in you just need to have any of the course from below:
BE / B.Tech in Civil/ Geo Informatics/ CSE/ ECE/ EEE/ Agriculture engineering/ Urban & Regional Planning/ IT (or) B.Sc. , Agriculture/ Forestry/ Horticulture (4 years) (or) M.Sc. , Geology/ Applied Geology/ Geo Physics/ Geography/ Geo Informatics/ Physics/ Maths/ Oceanography/ Environmental Science and Equivalent degree.

Please visit this link. I hope this will help you-
https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.shiksha.com/engineering/amp/gate-exam-pattern&ved=2ahUKEwjD6fek4YbiAhXT7XMBHT9pC0IQFjAAegQIARAB&usg=AOvVaw022LbBArFfXa9VkFueFFkk&cf=1

Yes, you should only clear GATE exam to take M.Tech admission.

A valid GATE score is required to take admissions for M.Tech.

Yes, you are eligible according to this rule one should have completed degree in (BE/B.Tech) aeronautical engineering or any other equivalent branches of engineering.

For answering your question i am attaching a link below:
https://www.shiksha.com/engineering/course/m-tech-in-food-processing-university-college-of-technology-osmania-university-tarnaka-hyderabad-288914

Hello Tanmoy, Yes, a student of mechanical engineering at undergraduate level can surely think of doing PG in aeronautical engineering. Of course the student can not select "avionics" as specialisation. However, any sub-branch of aeronautical engineering related to mechanical engineering can be selected if the student selects appropriate paper of GATE.
Best wishes for your dream of pursuing PG in aeronautical engineering.