Those are some good points LunarGoddess made. If you can't get a single room, nor is there a Pagan group, you could try talking to either your roommate or someone in the housing board to find someone fine with your practice. I never lived in rez but my friend did, and she had to fill out a brief questionnaire to try and find roommates with similar attributes [non-smoker, morning birds, so on] you might need to fill one out.
Another option, if it's spell casting, you can learn the others schedule and cast when they're out. If, however, you mean circles and worship, check if your college has a prayer room. Mine did, and it was for all faiths to have somewhere between classes to worship/pray. I went there a few times, and it was interesting to have a quick meditation becide someone who was Islamic and having a sunset prayer while a group of Christians were having a 'bible session' in the same room.
You do have many options to choose from if it's worship based over spell casting. Worship wise you could meditate, pray, go for a walk, light incense offerings, even keeping a plant for some people is seen as worship. Spell casting, try going with simple spells, like a candle spell, so it just looks like you're burning a candle.