Brother cheated me by acquring my half property

I am a married Muslim girl,My father passed away 20 years ago.I am having my mother and a elder sister and two elder brothers.One of my brother was taking care me and my mother as she was unemployed.When there was business loss to my brother he requested to share our father property for getting loan.So it was divided into 3 for myself and to my elder brothers.My elder sister and my mother agreed with not to have any share and only the right to live in the home and to have the income from the property till her death.During the partition brother asked half of my property to his name so that he can get more loan amount and he agreed to take care my education and marriage.For a safety my mother put asked him to sign another agreement if he do any thing wrong then the acquired property should be given back to me. During my marriage he has told to my mother that he will give a property with home to me instead of the acquired property.He has taken loan from my property and doing business in my pending property. Now he is not ready to give anything back ,telling excuses and he is also not taking care my mother.I don't know how to get my property back and need to file petition against him. Please help..He is financially strong enough to do anything against my family and my mother.