assalamoalaikum wa rehmatullahi wa barakaatuhu.
Hadhrat will my brother be Mahram of my mother in law?
Jazaak Allahu khairan
Wa Alaikum As Salaam,
No, your brother will not be a Mahram for your mother in law.
And Allah knows best,
Mufti Waseem Khan
This answer was collected from DarulUloomTT.net, which is operated under the supervision of Mufti Waseem Khan from Darul Uloom Trinidad and Tobago.