Design

Christ University does not offer interior design.

Yes, of course, it is approved by AIU.

Keep your CBSE studies aside. If you really wanna do something, Apply for NIFT. Practise sketching daily. There are two parts of the entrance exam, on the same day itself, prepare for the exam so you can get through it and enter the world of design.

For that you need to apply for Lateral's entry and there's an exam and interview for that also. If you get through it then surely you can go for it.

Degree gives more salary and reputation than diploma. Always keep that in mind.

Scoring a good rank can definitely get you a good campus and the department of your choice but for fee concession, you can apply for a scholarship. The scholarship is given on the basis of one's financial condition and the need. Through scholarship, one can get a fee concession up to 50% of the fee.

NIFT conducts it's entrance exam all over India for all of its campus all together in the second week of February, Though the forms are out by the month of November and the last date is usually in the month of January. There are two levels, after clearing the two one gets a rank on the basis of which admission is given.

There are many. You can try PRIME, Opus, Dezign Circle for the preparation of the entrance examination of Pearl Academy. You can even check the online practice paper available at the site of Dezign Circle which is very much useful to clear the exam.