Hi.

According to JOSAA rules ( https://josaa.nic.in/webinfo/File/GetFile?FileId=6&LangId=P ),

• A candidate who has been allocated a seat needs to download the “Provisional Seat Allocation Letter”. The candidate needs to accept the seat allocated to her/him and opt for any one of the options ‘freeze’, ‘slide’ or ‘float’ for the choice of academic program for subsequent round(s), if any, of joint seat allocation (see section XX).
• The candidate must upload the required documents (as per Annexure 3) on the JoSAA portal.
• The candidate must pay the seat acceptance fee. Admission fee varies across the Institutes/category of candidates. At the time of seat acceptance, candidates have to remit only the seat acceptance fee

Therefore, you need to pay the seat acceptance fee which is Rs. 15,000 for candidates with the category tag SC, ST, GEN-PwD, GENEWS-PwD, OBC-NCL-PwD, SC-PwD or ST-PwD and Rs. 35,000 for all other candidates (the fee includes Rs. 2000 JoSAA processing charges).

Also, this fee will be compensated by the same amount in your first semester fees of the college you are accepting the seat in.
Good Luck