What is the ruling on a father remaining in his job in the IT department of a usurious bank and spending his salary on his family, and what is the ruling on his daughter studying with a scholarship from this bank?

Your father is absolutely not permitted to work in a usurious bank, because it is not free of aiding those who deal in usury. Allah has forbidden cooperation in sin, and the Messenger of Allah, peace and blessings be upon him, cursed the one who consumes usury, the one who feeds it, its scribe, and its two witnesses. This is unless he is in an extreme, compelling necessity that cannot be averted except through that work; in that case, he may remain in it until he finds another job. The end-of-service bonus is unlawful money; he is not permitted to take from it except what suffices his need, if he is poor. The remainder should be disposed of by spending it on the welfare of Muslims or giving it to the poor. As for the daughter's education being paid for by the bank as a donation, it is permissible with some dislike.