Hi


For your wellness, take a new medical certificate to the reporting centre. Simply, because the JoSAA Official Memorandum too mentions the same. Ethically, you should produce a new and fresh medical certificate just before you take admission in a college. In short, make a new one. The Medical Certificate format is already given in the JoSAA Business Rules 2019. Take out a printout and do the formalities, you know that all.  

Also, do mention the same percentage of disability as mentioned in the original certificate issued by the Government of India. Do not mismatch the figures.

Best of Luck. 
Hope this helps.
Cheers!