What is the ruling on benefiting from my brother's money and sharing with him the payment for an internet subscription, and accepting his gifts and food, and using his personal tools, knowing that most of his money is mixed, part of it from unlawful work, and part of it is lawful from clothing trade, and a monthly allowance from lawful money?

If your brother's money includes unlawful earnings, it is permissible for you to use the internet for which your brother pays the fee, and there is no harm in you sharing the payment of the fee with him. Similarly, it is permissible for you to accept your brother's gift, eat his food, and benefit from his tools that he purchases with his money, because dealing with someone whose money is mixed [with lawful and unlawful sources] is permissible.