I’m applying to Northeastern and am trying to plan which college I want to apply to within the University. I was thinking of applying with a major in the College of Science. Would I be able to do a minor in the School of Health Sciences?
Yes, this is quite common. Wirth rare exception, there are few limits between colleges for taking classes or even switching colleges. A big reason is that Northeastern admits to the university as a whole, not by college.
In case there’s any doubt, this is the first sentence on the Health Sciences minor page: