Diploma

Instead of doing Diploma in mechanical engineering, you should go for 12th class education and then take admission in mechanical engineering. The reason is that Government of Maharashtra is about to ban Diploma in mechanical branch. So, for making a career in the mechanical field, it will be beneficial for you to complete your class 12th.

Of course, you can do aeronautical engineering.
After completing any Diploma course in mechanical branch you can go directly to the 2nd second year after completing the Diploma.
I completed Diploma and the joined aeronautical engineering college.

You should take mechanical engineering in B.Tech. You can also undertake various designing courses like Catia, Creo or Ansys that will surely help you in future.

You can surely take PG Diploma in medicolegal science, you just have to have the required qualifications for the course and then apply in the college and if selected you will be contacted.

Hello Mohammed,
After completion of diploma in mechanical engineering, you are entitled for lateral admission to 2nd year in Aeronautical Engineering branch in any college but in your own state. However treating your diploma as equivalent to 12th, you can get admission in 1st year in IIT also.

If you Diploma in Computer Science and Technology course, it would surely benefit you. After this, you can get admission in any college directly in the second year and also you will have some prior knowledge about it too which would surely be beneficial for you.