What is required of my father who was forced to wear sewn garments during Hajj due to extreme health necessity?

If a pilgrim in a state of ihram wears something forbidden due to necessity, such as illness or the like, he must pay a fidyah (expiatory sacrifice) but incurs no sin due to the excuse. This is based on the Almighty's saying: "And whoever among you is ill or has an ailment of the head - then an expiation of fasting or charity or sacrifice." (Quran 2:196) And on the Prophet's (peace be upon him) saying to Ka'b ibn Ujrah: "Shave your head, and fast three days, or feed six needy persons, or sacrifice a sheep." Therefore, your father is obligated to pay the fidyah, which is one of the three aforementioned options.