Hello
Most colleges consider the marks of Physics, Chemistry and Mathematics in Class 12th for admission to Chemistry (Hons). Also, you should atleast clear the Mathematics exam with average marks to get admission in any decent college.
Moreover, if you want to pursue Chemistry (hons), knowledge of Mathematics is also required in the subject. So, you should study well. Mathematics is not very tough subject. You need to have proper understanding of the subject.
Good Luck!