Is my father considered a suicide if he fell from the fourth floor, and what can I do so that he does not enter Hellfire, knowing that he was religious?

Suicide is a grave sin, and its ruling, severity, and the fact that its perpetrator is not considered a disbeliever have been addressed in previous fatwas. One should not accuse a Muslim or harbor ill thoughts about them, especially if they are a father, religious, and pray with the congregation.