Hello,

No that won't  happen as entrance normally start by april where all the board exam works are completed. They schedule the exam is such a way that it won't clash with any exam conducted in your state or at national level.

There are officials to take care of that. so don't worry and give your time for preparation.

you will get around a month time to the entrance after your board exam. you can prepare the 1st year concepts more deeply and focus on numericals and theory parts of physics and chemistry.

Hope it helps!