Diploma

Based on your interest and skill sets, decide which course under Diploma you want to do. Diploma can be pursued in engineering or in any of the designing courses like fashion, interior, textile etc. Or perhaps hotel, hospitality and travel and tourism industry. You should have passed 10th successfully.

Yes, there are Diplomas in entertainment industry - fashion industry, textile designing, beauty courses and hair dressing, film acting, screen play and direction, creative writing, theater and fine arts.

It depends on your interest and skill sets. There is Diploma engineering, Diploma in varied designing courses like fashion, interior, textile, apparels etc., Diploma in hotel, hospitality and tourism and Diploma in animation, beauty culture courses.

I am giving you an unbiased advice naturopathy is not a good career option, because there are very less jobs available, and it has very less salary people are not much aware of naturopathy.

Yes, you surely can. AICTE has given this task to the institutes to decide the eligibility for admission in any course. So, if you can convince the administration that your course is similar to Mechanical and that you would be able to study B.Tech without any problem. Then they may give admission.

You can take admission after the gap by providing a self-declaration stating reason for your gap. That can be easily made by paying 50rs. To a notary lawyer. All colleges take admission this way. You just have to check your age and marks eligibility.

Yes, you certainly can. Diploma courses can be pursued after passing 10th class. There variety of Diploma courses you pursue. You can search for your desired Diploma course here. https://www.shiksha.com/engineering/colleges/diploma-courses-india.

It depends on what is the eligibility of the course. If the course requires the entrants to be class 12th pass, and you have got compartment in 1/2 subjects, then you may be given admission provided you clear the qualifying exam in compartment exams.
In case the eligibility is just class 10th pass, then you can get admission. It will not depend on your class 12th results.

That is a very nice career choice you have made. I hope you are pursuing B.Tech in Aeronautical Engineering. This is a great course and will surely open opportunities for you in aviation sector. The demand for such courses has increased in past years due to rapid development in the Aviation Industry. The demand for aeronautical engineers has also increased no doubt. So it would be a very good experience for you. All the best for your future.