Diploma

Hi!
You can refer https://www.shiksha.com/careers/architect-13.

Yes you can as the minimum eligibility is class 12th
Details : https://www.shiksha.com/aviation/flying-pilot-training/course/training-for-commercial-pilot-s-license-government-flying-training-school-yelahanaka-bangalore-117397

Please specify the course name for which you require information so that I may be able to populate relevant information.

Go through the link below for details :
https://www.shiksha.com/hospitality-travel/travel-tourism-chp

Yes, you can. But choose branch carefully because options available are plenty.

The admission in NITs are based on JEE-Main ranks and 12th marks. The minimum required percentage for admission in NITs at 12th level is 75%. On the basis of diploma you can not get admission in NITs. Hence on the basis of your 12th marks you are not eligible for the admission, if belongs to general category.

You can apply for any course after your graduation, but you need to consult firstly the higher authorities for the same, and this course is nothing to do with your class 12th grade marks. All the best.

You can apply anywhere, as it is of 1 year and eligibility should be 10+2. Or else, you may go for degree also that will be of more value instead of Diploma. So, you can opt of MBA or B.Com. Rest, choose what allures you the most. All the best.