What is the ruling on gifts brought by a brother who used to work for a company selling pork, and is now receiving unemployment benefits after being laid off?

There is no blame upon you for accepting gifts from your brother and benefiting from them, whether they are from unemployment benefits or if his money is mixed with unlawful earnings, due to the permissibility of dealing with someone whose wealth is mixed. You should advise your brother to dispose of the unlawful money he earned from selling pork by giving it to the poor and needy as an act of repentance. He should not benefit from it himself unless he is poor and in need of it, in which case he may take according to his need.