Dear student,

If you do not got allotted seat in josaa round counselling you can participate in csab round counselling.
And if you withdraw from josaa counseling, then also, you can participate in csab special round counselling. Because anyone who has not participated in josaa counselling or has not got allotted any seat in josaa counselling, can easily participate in csab special round counselling by paying a participation fees of Rs. 36500. And if you got allotted any seat in csab special round, then you can accept it by paying the seat acceptance fee of Rs. 35000.

But it's not necessary that you must have to withdraw your seat. You can also accept the seat and can participate in csab round counseling by retaining your josaa seat , but only you will have to pay the registration fees. Also if you get any seat in csab round counseling and accept it, then you will not have to pay the seat acceptance fees, because you have paid once in josaa counseling. And your josaa seat will automatically get cancelled.

Also check out the following link to know more about the eligibility criteria and more information about csab special round counselling :-
https://engineering.careers360.com/articles/csab-special-round-for-nits-iiits-and-gftis