CBSE 12th

If the marksheet of Class XII (or equivalent examination) for 2025 is available, then it must be uploaded. If the candidate's name is not the same as in the Class X certificate, a gazette notification showing the change of name.

Candidates belonging to SC/ST/PwD require to score a minimum of 55% marks in aggregate or equivalent grade in their Class XII (or equivalent) examination. Candidates belonging to other categories require to score a minimum of 60% marks in aggregate or equivalent grade in their Class XII (or equivalent) examination.

Yes, if you want to raise your grades, you can retake the Class 12 exam in 2025 as a private candidate.

Yes, NITs will accept your improved score only if you have only 73% in your 12th borad. You are adviced to appear for improvement exams only if you are from general category as the minimum requirement to appear for JEE is 75% for general. But if you are from other category such as SC/ST, you need not to appear for improvement exam as you're already eligible for JEE. So the answer of your question is yes, the NITs will consider your improved score only and you're adviced to appear for improvement exam only if you're from general category.