Hello,

If you want to take admission in BSC mathematics or MSc mathematics then math is compulsory in your 12th class for every colleges. And BITSAT is mainly entrance examination for Birla institute of technology and science college. If they are suggest you that yoi have to giving pass subject mathematics in chemistry honours then compulsory you have to mathematics in 12th class. But due to research there was no this kind of order found. You can talk to the college authority directly i think it would be better for you.

All the best.