if you have not filled the form of JEE in 2019 i.e you have not filled the form 2 times of JEE and you have 75% in your 12th of CBSE boards or you are in top 20 percentile  of your respective boards, then you are eligible for JEE advance 2020..

Hello,

Yes, you are eligible to apply for JEE 2020. You cannot directly attend JEE Advanced. In order to appear for Advanced you should score above cut-off in Mains. You can attend JEE upto two years after completion of Class 12. Also now you can appear for JEE twice a year, one in January and another in April.