hey,

i hope you are well

sorry to say but you are not eligible to write JEE mains and advanced as the basic eligibility for the year 2020 says candidate must have passed their 10+2 from recognized board , if you will be eligible to write both the exams when you appear for compartment and get passed in same , you will be needing a 12tn grade passing certificate to appear for JEE mains and advanced.

hope this helps!