Surgery in few hours and have a tickle with occasional dry cough.? I don't want delay. Can I hide this?

Do not hide. Hiding any symptom from anesthesia is dangerous. Anesthesia itself has risks and the anesthesiologist needs to know about any and all symptoms you are having at the time of surgery. If it is an elective procedure, more tests may be needed to make sure you are in the best possible health for the procedure. If emergent, the anesthesiologist can be prepared for possible complications and treat them.