If your question is regarding NCHMCT JEE 2020 which you have tagged then you will be glad to know that there's no minimum percentage requirement to be eligible for NCHMCT JEE .
To be eligible you just need to be either appearing or should have passed 10+2 examination.
Also to be eligible, you must have English as one of your subjects in 10+2.
Also there's upper age limit of 25 years as on 01.07.2020 for general and obc category while there's upper age limit of 28 years as on 01.07.2020 for sc and st categories.
For detailed information go through our page for which link is provided below