Which is the best course among B.Sc nursing and B.Sc radiology?

Radiology seems to be having better paying options.

Radiology is the best option. As you are a boy, I feel that if you go for the further higher studies in this branch, it means the span of time and experience, you can become a professor in MBBS colleges. If it is nursing, there may be no scope.

There is no difference between them, both are the supporting careers.