What is the ruling regarding a father performing the funeral prayer for deceased individuals upon whom the funeral prayer was not performed, and whose graves are scattered?

If the graves of the deceased are unknown, they are treated as absent deceased, and it is permissible to pray over them, especially if it is known that no funeral prayer was performed for them. So, whoever dies and their place is unknown, the funeral prayer for the absent is performed for them. What the father wants is permissible, provided that those he wishes to pray over meet the conditions for the validity of the funeral prayer for the absent, the most important of which is that the deceased was a responsible Muslim at the time of their death.