Is the money from the sale of my brother's house permissible (halal), and are the money and gifts sent by the brother residing in the West permissible (halal), knowing that he works as a tailor and claims to work as a priest?

The money your brother received as compensation for selling his house to your other brother is permissible (halal), as long as the sale fulfilled the [Sharia] pillars [of a valid transaction]. There is no evidence for the impermissibility of this money. Merely speaking about a brother without evidence does not prevent benefiting from his earnings; rather, it is considered backbiting (gheeba), which is forbidden. The fundamental principle is that one's financial integrity is presumed until proven otherwise.