Hello aspirant,

You need to specify which grade/class you are talking about. If you are in 12th PCM and failing chemistry, I don't really think that the college will pay much attention to it, but then it depends on the college as well. if you are going to tier 1 college (DU, BHU, etc), they consider your overall performance for their merit list. But some colleges don't bother with your marks in 12th (like Christ University)

But if you're failing chemistry and it is in turn affecting your promotion from 12th or you fail class 12th because of it, no college would consider your application.