Dear aspirant,

suppose you get a compartment this year then you will get a chance to appear for the compartment exam before the counselling of main main and advanced.

Suppose if you didn't get compartment but your overall score is less than 75% then you must have to appear for all the subjects in improvement to be eligible for NIT and IIT. IIT and NIT do not accept improvement if you have not appeared for all the subjects.

Hope this helps. Thank you.