Those are both fine. They make sense and can be understood. You should probably try to give a few more details, and remember it is a conversation with a receptionist. You will need to respond to his questions :
Hello, can I help?
Yes, is there any patient called Ali? I'm here to visit him
Do you have his full name?
Um, it's Ali Uckan.
And do you know which ward he's on?
I'm not sure. He broke his leg.
Well let me check...Ah yes, Ali Uckan on the Jean Brodie ward, second floor. Visiting hours are from 2 to 4 weekdays. If you follow the signs to your right.
You see I've used your phrase but I've added my purpose (to visit), full details (last name) and I've coped with not being able to answer the question (what ward) by giving information that the receptionist might be able to use (the nature of the injury)
Remember the receptionist is being paid to help. They will be more tolerant of mistakes, and listening carefully to you, so don't worry too much.