Diploma

Please refer to the link provided below for details regarding a Diploma in Aviation, Hospitality and Travel Management from Frankfinn Institute of Air Hostess Training. You should be able to download college brochure which contains details regarding admissions and eligibility criteria for this course. Alternatively, visit college web site for further details regarding this course.
https://www.shiksha.com/aviation/course/frankfinn-diploma-in-aviation-hospitality-and-travel-management-frankfinn-institute-of-air-hostess-training-rajouri-garden-delhi-235194
(Website: http://www.frankfinn.com)
Regards.

Please refer to the link provided below for details regarding a Diploma in Fashion Design from World University of Design. Important details like course eligibility, admission process, fee structure, etc. are mentioned at this link. Regards.
https://www.shiksha.com/design/fashion-design/course/diploma-in-fashion-design-world-university-of-design-sonepat-298948

Yes, Jain University offer admissions to Diploma students directly in the second year.

This is the admission or eligibility criteria for B.tech.
B. Tech. Eligibility Requirements
Age: Applicants whose date of birth, as per school records, falls on or after 1st July, 1997.
Educational Qualification: A pass in 10+2 (Class XII) or its equivalent examination securing an aggregate of 60% marks in Mathematics, Physics and Chemistry with not less than 55% in each of these three subjects.If you have completed Diploma with 12th then yes you are eligible.

Please check for your eligibility to apply for a Post Graduate Diploma in Computer from Suresh Gyan Vihar University Distance Education - Talentedge, Ghaziabad from the criteria mentioned below:
Basic eligibility to apply for this course is that candidate should have completed their graduation with Mandatory Courses : B.E. / B.Tech, BCA, B.Sc.
Candidate must have completed B.Sc with Mathematics as subject securing 45% marks or B.E/B.Tech/BCA or any master degree in any subject.
Admission Process:
Interested candidate can apply directly to the college.
Regards.

Minimum eligibility to apply for Diploma in Physiotherapy from D.S. Institute of Paramedical Science and Hospital is that candidate should have cleared class 12 with Mandatory Subjects : Physics, Mathematics, Mathematics / Biology. Candidate must have passed 10+2 from a recognized board.
Admission is based on the marks obtained in 10+2. Interested candidates can apply online with the required information. Regards.

Yes, you can do mechanical Engineering but I prefer you to go with aeronautical because there are lots of scope in it.

Yes, you can do Diploma course with regular MBA as a external. But, you have to take care of semester exams of both the sides.

There are many colleges for Diploma in Automobile Engineering. Click the following link to check the top colleges providing Diploma in Automobile Engineering. Find a good college according to your elegibility. https://www.shiksha.com/search/?q=Diploma+Automobile+Engineering&sp[]=45&qer=0|0|0|0|0|0|45|0|0|0|0|0|0|0|10|0&sa=^0^0^45^0^0^0^0^0^0^0^10^0^0&rf=searchwidget&cr[]=10&pn=1&sscs=1&tk=Diploma+Automobile+Engineering&s[]=2&tscs=1.