Focus on completing the NCERT first. If you are able to the NCERT (for which you have approximately 2 months now), you will score really good in boards as well as above average in JEE Main.

Ensure that you complete NCERT thoroughly, solve each and every question and example given in the book. This will almost ensure 75%-80% marks in the boards, which will make you eligible for admission in government colleges like NIT, IIT and other centrally funded institutes.

If you are not able to clear the JEE Main, drop for an year if you are sure about your capability and interest in engineering.