Are you asking for JEE Main entrance Exam? If yes then as per the official a Person with Disability (PwD) with 40% or more disability will be eligible for this quota. You can also assure about it with the given below link the given information on Page No. 13.

https://jeemain.nic.in/WebInfo/Handler/FileHandler.ashx?i=File&ii=88&iii=Y

Good Luck!