Don't do it it's not fair on the animal. Don't buy an animal until you're financially secure enough not only to feed it but to get insurance, pets get sick sometimes and it's doubtful you'd be able to afford veterinary treatment which is VERY expensive. Not to mention you'll be moving several times through your time at uni and cats hate that it'll be very stressful for the cat and all because you were too selfish to think about it properly and wait.
And that's not even taking into account that you're not allowed pets. If they find out what are you going to do? Just stick in a shelter or get kicked out? Lets be honest, you'd get rid of it.
If you honestly couldn't think of the downfalls and why you shouldn't then you're not mature enough to be responsible for another animals life and well being