If you have recently updated your aadhaar card, then you have to apply by entering 14 digits Aadhaar Enrolment ID/UR No. (Including slash) printed on the slip issued by the aadhaar center.

Also, it is not mandatory to apply with the Aadhaar number. Candidates can use a Passport number, Ration Card number, Bank Account number, or any other valid Government identity number while applying for JEE Mains.