Is it permissible to delete channels that broadcast immorality, debauchery, and false beliefs without the father's knowledge?

It is not permissible to witness or listen to falsehood except for a valid purpose, as Allah says: "And those who do not witness falsehood, and when they pass by ill speech, they pass by with dignity." You should admonish your father gently and kindly, and supplicate for his guidance. If he does not respond, then leave him, for a father is not like a stranger. As for deleting channels without his knowledge, this often leads to a greater evil. It is sufficient for you to admonish him verbally and seek help from those whose words he accepts, while continuously supplicating for his righteousness.