What should I apply for after 12 SCRA Or IIT? Right now I am in 11th and scored 90.6% in 10th ICSE board.

Hello student that depends on your intrest both are two different thing for iit you need to clear jee advance and for scra you need to prepare for it.
As eligibility criteria says The eligibility criteria is as under;

Age:
17-21 years
3 years relaxation for OBC (non-creamy layer) candidates
5 years relaxation for SC/ST/PD candidates.

Education:

Passed 12th (Maths + Physics/Chemistry)or equivalent from some recognised board with first or second division.

Also, B.Sc. (Maths/Physics) are eligible to apply for the exam.

Kindly refer the last year SCRA advertisement for complete details about the eligibility criteria.

Also
Careers360 is conducting the All India Talent search exam where students of 11th and 12th PCM/PCB can test their knowledge and enhance their preparation by knowing their stronger and weaker areas and win prizes and scholarships worth 1.25 Crore.
If you are an Engineering or medical aspirant, it is a great opportunity for you. Take the test, perform the best, avail the scholarship and win prizes.

You can win exciting prizes such as:
50,000/- cash Prizes, Upto 100% Scholarship on JEE / NEET AI-Based preparation packages, Laptops, Smartphones, Amazon Echo, Careers360 Almanacs, Powerbanks, Upto 250/-  paytm *Cashback offer

Link: https://learn.careers360.com/careers360-talent-search-exam/?icn=qna&ici=interns.

Feel free to comment if you have any doubt
Good luck