Hi Anup,

There are a maximum of three attempts allowed for JEE Main in consecutive years, the first being the year you pass your class 12th. So, the answer to your question would be, Yes, you would be eligible for JEE Main 2020 if the year you passed class 12th for the first time is 2018.

No, your board does not matter in placement, what matters is your skills and CGPA after the end of your graduation.

All the best