My dad had been coughing blood is it normal?

Not normal. Most common cause of hemoptysis (coughing up blood) is bronchits and pneumonia. Many other possibilites exist especially if he is a smoker including blood clots, cancers, infections, circulation abnormalites, pulmonary embolus, bronchiectasis to name some. Most commonly a small blood vessel in the bronchiolar circulation breaks from coughing but would get medical evaluation and chest xray.
No... Coughing blood is never normal and since malignancy can cause coughing blood, it is a symptom that needs a doctor to evaluate to be sure there is no malignancy present. It can also be due to bronchitis which is also the most likely reason for coughing blood, or hemoptysis. If your father smokes, he needs to quit to decrease airway inflammation.