What is the ruling on giving money to a brother who spends it on alcohol, knowing that not giving it to him leads to problems and perhaps crimes?

It is not permissible to give money to one's brother if he uses it to disobey Allah, as Allah the Almighty says: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression." You must advise him and remind him of the impermissibility of his actions and Allah's punishment. If he does not respond, his case should be referred to the courts to be dealt with legally. Brothers are advised to deal with him through legal means to prevent his harm if they do not forgive him.