Hii Aditya,

yes yo can appear in JEE main and JEE advance too.

and remember,

there is no any 12th marks wise eligibilty criteria is defined for appearing in jEE main.

every one who has passed or going to give 12 exam can appear in JEE main.

the 75 % about which you are talking, is minimum Eligibility criteria for Getting admission in NITs or IITs.

many Government colleges take admission on below 75%.

and when you will qualify the JEE main then you will be eligible to appear in JEE advance.

thank you 

Hii Aditya

Firslty congratulations on achieving such a great score in you class 12th boards exams . Yes you are eligible for applying and appearing for the JEE mains exam as well as the JEE advance after clearing your JEE mains. You have fulfilled the basic critirea for being eligible to appear for the JEE mains. Best of luck and you can visit this link by our Engineering experts -https://engineering.careers360.com/exams/jee-main

Hope it helps

Thanks