Kashan you can upload your new OBC NCl certificate on JEE Advanced website.

First of all visit https://www.jeeadv.ac.in/ website there, you will find a big caption as "Candidates can upload their corrected/new/proper certificates on the candidate portal". Click on it login to candidate portal by entering all the information asked (registration number, date of birth etc.) and you can upload your new caste certificate on that portal.

Make sure you do it quickly because the time deadline hasn't been mentioned on the website.

Feel free to ask if you have any more queries. All the best!!