Dear student,

CSAB is a special round counseling conducted by central seat allocation board to fill the vacant seats in nits, iiits, or gftis. As per your rank in ews category and your rank 13663, then yes, you can get the seat in jec with cse branch but the chances are very low in CSAB round. And if there is not any seats vacant then you can not get the seat in jec.

And if you want to fill ews category jn jossa counseling then yes, you can apply it but you must have a valid proof for ews category. Because if you get a seat and at the reporting center you have to produce your category proof and if you fail to produce then you will be caught. And such act will lead to rejection or cancellation of your candidature and you will not get the admission.

You can check out the given link below to know more about jossa 2020 counseling :-

https://engineering.careers360.com/articles/josaa-counselling

And coming to your 4th question then yes, you have to register again in CSAB and the registration fees for csab is around INR 35000. It doesn't matter that you have registered in jossa or not. Csab is a special round and you have to pay fees to get yourself registered separately. If you didn't got any seats in jossa and you want to sit in CSAB round counseling then get registered yourself by paying the fees and if you get any seat in CSAB counseling then again you have to pay the seat acceptance fees.

You can also check out our college predictor tool to get more appropriate idea of your chances of getting the colleges based upon your rank :-

https://engineering.careers360.com/jee-main-college-predictor?icn=QnA&ici=qna_answer

I hope this will help.