hi,

see jee main has no minimum 10+2 marks criteria for appearing in the entrance test. however if you are interested to join in nits or iits or gftis etc you need to have either in top 20 percentile of the respective board from which you have passed 12th course or  75% marks (general category) in 10+2 course in aggregate, for sc/st it is 65%.

hope you may understand. follow the below link to know in details,

https://engineering.careers360.com/articles/jee-main-eligibility-criteria