Which is a better option considering future aspects, B. Sc. (H) Mathematics or B.Sc. Program (Computer Science) ?

today there is good demand for maths , there are lots of candidate for computer science but not for maths

I can see a crowd in Bsc Programming (CS). It gets added with Diploma in Comps/IT, BTech in Comps/IT, BSc -IT, BCA. If you want to challenge this crowd then opt BSc (Comps) otherwise BSc (Maths).