BHM

Scope is a qualitative factor and hence cannot measure and tell which is better. Both BHM and B.Com are having more potential in their own way. Both are three year undergraduate courses.
For BHM students, the chances are very bright. You will have lots of scope in both private and public sectors. You can find work in fields like hotel and restaurant management, guest houses, lodges, merchant navy, airline and catering service, etc. after completing graduation.
However, some differences here are when it comes to B.Com, most of the subjects are accounting or finance subjects unless of course your specialization is otherwise. It gives you employment in a business house, export company, financial organization, banking sector or teaching profession.
There is no restriction on doing these courses for even Science students. However, a science student will find it very difficult doing B.Com since it largely involves accounting related subjects. However, a science student doing BHM will find it easier to manage with the course since they are more practical.