You can certainly request a specific room, but the chances of it being vacant for the time you want/need it are small. Very specific requests are almost always a receipe for disappointment.
It's usually recommended to request general things so the assigner knows what you really want. For example, if the specific room isn't available, the assigner won't know why you wanted that room - was it the higher floor, the view, the proximity to XXXX, the type of bedding or ????. You're likely to end up with something completely opposite to what you were hoping for.
Best wishes -