Design

You can refer the below link:
https://www.shiksha.com/college/national-institute-of-fashion-technology-kolkata-salt-lake-city-27351

Hi Sanskar,
A student must be 10th pass from either The Central Board of Secondary Education Examinations (CBSE), The Council for the Indian School Certificate Examinations (ISCE) or Other certificates equivalent to GCE O level. Also, applicants should be 16 years of age or above in the year they are admitted to Year 1 of the diploma course. Details are easily on the website. Check here:
http://www.nafa.edu.sg/courses/diploma/diploma-in-design-(interior-exhibition)#collapseEntryThree

The choice of location Chennai or Bangalore is a matter of comfort for a student based on presence of close relatives or friends, general like or dislike towards a particular city for any reason, etc. The course is same in all the locations. As all the campuses have separate validation by the university, the standard of education, facilities, fee structure and duration everything has to be maintained at equal standard. So choose the campus based on your liking about a place. But I am afraid whether you will get a seat now as the admissions has entered its last phase and seats for most of the courses are over for this academic year.

You need to check with the admission cell on this. You can change but they are the better person to guide you.

You can refer to the below link mentioned below:
https://www.shiksha.com/design/interior-design/colleges/colleges-india?uaf[]=location&ts=6904753&rf=filters&ct[]=10224

Yes, after completing Diploma in interior designing with a minimum of 50% marks, you have to qualify the National Aptitude Test of Architecture to appear for AIIA exam.

You can refer to the link mentioned below:
https://www.shiksha.com/college/army-institute-of-fashion-design-kothanur-bangalore-25016