Praise be to Allah, the Lord of the Worlds.
Whoever borrows money for a lawful matter and becomes indebted as a result isn`t required to sell his land and house, which suit a person of his status. Although he owns the afore-property, he is still considered poor and indebted. It is stated in [Bushra al-Kareem, pp.525] "Owning the house where he lives and which he needs doesn`t make him other than poor." Kindly refer to some commentaries on [Shorooh al-Moftaah, vol.1/pp.258].
No one can force you (Questioner`s brother) to sell your land and house, which suit people of your status unless the court decided to sell them to settle the debt. On the other hand, it is permissible to authorize your brother to receive the Zakah on your behalf and to pay your debt as well. And Allah The Almighty Knows Best.