College Students (and really, anyone) should attend a worshipping community where they can feel welcomed, inspired and challenged. The proximity of this community does not matter (that is, unless it is 100 or more miles away!). So the simple answer to your question is no, you do not have to stay at your local parish when you go off to college, but you can stay at your local parish if it is a community that feeds your spiritual needs and is fairly easy to get to!