What is the target heart rate in patient with Afib, my father heart rate is between 47-57heis on metoprolol suc.75mg and cordarone (amiodarone) 300mg?

AFIB. What is his blood pressure? The heart rate you report would be considered reasonable, provided that your father is not having symptoms such as fatigue, lightheadedness, dizziness, chest discomfort, shortness of breath. If he is having symptoms (at rest or with exertion), then likely that rate would be "off target" for him, and a follow-up appointment with his cardiologist would be in order.