if brother is not listening then there is no option left. there are henpecked men.
provoke her to abuse and threten you, dont shout at her or curse,record all her abuse in your mobile and keep it in your original mobile only. do not tell anyone.
once you get such evidence 2/3 times you can approch Police
as she can dial one number you can dial one number too….
so with all your proofs make a petition to police on your mothers behalf and file Domestic Violence case on your brother with your mobile evidence and ask court to restrain him from coming 100m near to your parents house. he asked for it, he will get.
read more about DV here http://mynation.net/laws/bare-acts/pwdva/pwdva.htm
call our Delhi numbers if you need any guidence. http://mynation.net/contact-us/