Graphic design

There is no particular eligibility criteria for the certification in graphic design, but you need to complete class 12th.
Go through the link below for more details:
https://www.shiksha.com/design/communication-design/colleges/graphic-design-colleges-india

Yes, you can pursue graphic design course after class 12th. There are many design institutes offering B. Des in graphics. You can visit websites of various institutes and universities.
G D Goenka
NIFT
NID
APEEJAY INSTITUTE OF DESIGN
IIAD.

NID in itself is a highly reputed organisation and I believe if you step into any organisation to work as a graphic designer won't fetch you a growth rate faster enough to showcase your talent as experienced in an institute like NID because the industry is currently undergoing a bit of its recession period. Therefore, it would be really best that you step into NID course first and avail a wonderful job opportunity without having wasted your time to cope up with present IT circumstances.

Please check for your eligibility to pursue M. Des from the criteria mentioned at the link provided below:
Master of Design (M. Des. ): Eligibility:
The eligibility to pursue Master of Design, one need to have a Bachelor of Design or Bachelor of Architecture degree with a minimum of 50% marks. There are several universities which are offering Master of Design from distance learning also. Their list is as followed:
Amity University, Noida
Aesthetic College of Interior Designing, Calicut, Kerala
Delhi Institute of Technology and Paramedical Sciences, New Delhi
Regards.

Kindly click the link below to read an article about Graphic Designing. https://www.shiksha.com/animation/graphic-web-design/articles/graphic-designing-as-a-career-the-visual-sorcerer-blogId-3581.

For Graphics designing, government colleges are the best as, placement is a surety. But, other institutes also offer the same with good placements, but the fees is exceptionally high. The government ones are NID Ahmedabad and NIFT Delhi, IIT Bombay. Other NIFTs are also good but for graphics, NIFT Delhi is best among all. In the private ones, Pearl Academy Jaipur and Delhi are really good. Other than these, Shrishti School of Art and Design, Trivandrum, Indian School Of Design And Innovation, Mumbai
GD Goenka School Of Fashion and Design, Mumbai etc. are some good options.

Graphics and animation comes under designing and to be eligible for any design course, including the above mentioned, most of the colleges have minimum 55% criteria.

It depends on your interest. Interior designing is more into creativity, wall color and furniture design for the room, but B.Arch is more into the map of an area and its structure.

Hello Dear,It is all up to you, your interest and your creativity level. Both fields has equal importance and opportunities.