Definitely your first and foremost priority should be preparing for neet only..
And my advice to you is that it does not matter from which state board do you belong because all state boards are easy as compared to the thing you are preparing for and if you go through the ncert of 11th and 12th required for neet then you almost go through each and every topic and just before your board exams you just have to read and practice the way you have to represent your answer because you know the answer at last if you have studied for neet whole year…
But the board pattern is different and 20 days before the papers are more than enough to prepare for your boards….
And at last the most important thing is it does not matter how much marks you got in your 12th standard but the thing that matters is whats your neet score and did you passed your 12th with first division or not…
Believe me I have gone through that…