Hello,

Yes, you can participate in CSAB (Central Seat Allocation Board) after freezing a seat in JoSAA (Joint Seat Allocation Authority) Round 5, even if the seat is in the NIT+ system. Here’s how it works:

Freezing the Seat in JoSAA Round 5:
Once you freeze a seat in JoSAA Round 5, you are confirming that you wish to keep this seat. If you later participate in the CSAB Special Rounds and you do not get any better seat through CSAB, you will retain the seat you froze in JoSAA.

Participation in CSAB:
You can participate in the CSAB Special Rounds even if you have already frozen a seat in JoSAA. If you do not get a seat in CSAB, your frozen JoSAA seat remains safe.

Retention of JoSAA Seat if No Seat is Allotted in CSAB:
If you are not allotted any seat in CSAB or choose to reject any offered seat, your JoSAA seat will not be cancelled. You will continue with your frozen seat from JoSAA Round 5.

This allows you to explore better options in CSAB without the risk of losing your existing seat.

Hope it helps !