Is it ok to take propranolol 20mg with Xanax (alprazolam) 0.5 mg.

Depends. The two can be taken together if indicated but should be started when you are at home . Propranolol and Alprazolam may have additive effects in lowering your blood pressure. You may experience headache, dizziness, lightheadedness, fainting, and/or changes in pulse or heart rate.
Inderal/Xanax. Added sedation & lowering of blood pressure is expected. Review with your doctor.