Hello Sanket,

No, the registration fees is a one time payment and is not refundable if one doesn't get a seat. Basically it is a application fee and is paid after filling up the registration form. Below I have provided the CSAB Special Round seat allotment process - 

• Regustration : Candidates have to register for CSAB Special Round by using their JEE Main application number and password.
• Participation Fees Payment : After registering, candidates have to pay the required application fee through SBI MOPS payment gateway.
• Choice filling and locking : After the completion of payment, candidates have to fill up their choice of colleges and branches as per their preference.
• Announcement of seat allotment : The authorities will allot seats on the basis of JEE Main merit,choice filling and seat availability.
• Seat confirmation fees payment : Candidates who have got seats have to confirm the same by paying the required fee.
• Online reporting to the allotted college : Candidates have to report online to the college allotted by using their JEE Main credentials. Also, they have to upload the required documents.
• Personal reporting to the allotted college : Candidates have to report to allotted institute within the specified time period.

You can also go through this link and checkout the details regarding CSAB Special Round counselling : https://engineering.careers360.com/articles/csab

Good Luck !!!!