Hello bishal,

don't  worry about percentage. just give your best in your board exam. there are so many entrance exams which consider very less percentage. Mostly entrance percentage cutoff is in range 50-60% minimum aggregate.

You can't change your stream now. there  are so many options available. You can search it.

get your results then decide what you will choose to make your career.  there is way and solution for every issue and problem.

thanks