Well I would assume that being enrolled in a college means that you would have to register legally that your sex is female and not male (yet). That's how it is at my school. It's like the whole legal name thing and preferred name thing.
But as far as I am concerned, if you are biologically female you would have be on a female team and vice versa (I believe the reason is because of the high competition in the different sports division. There would be difference in strength and all). But, I guess if you want to you can talk to whoever the head of the physical education department is at your school and maybe you can work something out with them.
Believe it or not, being 5'3" and 145lb, I play rugby with a bunch of my male friends who are all 5'11" and over (And big guys!). And honestly the majority of them knows that I'm biologically a girl and they're completely cool with it and they met me as a guy. But then again it's different for everyone depending on your demographics. Either way, I haven't had any bad experiences with coming off as a guy in sports just yet.