Now, there is no IIT-JAM entrance for MCA program so if you wish to get admission in MCA then you can apply for NIMCET exam and if you clear it then you are eligible to get seat in NITs.

Also, candidates who are the graduation degree holders (BCA/B.Sc (Hons.)/B.Sc/BIT) as per 10+2+3 pattern from a recognised university are eligible to apply. Candidates must have studied Mathematics or Statistics or equivalent subject during graduation and the application window opens in the month of Feb-March.

For reference, you can go through the below links and let me know if there is any doubt -

https://it.careers360.com/articles/nimcet-eligibility-criteria

https://it.careers360.com/articles/nimcet-important-dates

Good Luck!!!