A married daughter's right to parents property

Respected Lawyer I am married women staying with my husband and children since 1990 and my father family has 6 son and 2 daughter of which one sister is staying abroad and out of 6 brother 3 have expired and 3 brother are staying seperately and one brother wife is staying with my father's family with his 14 years old son.My father is Hemiplegia for more then 10 years and he has sold his factory and some amount invested in Gujrat and few amount kept in interest with one of the builders because my father can not speck and Hemiplegia so my husband has requested to me father to make power of attorney in my brother name to look after all the activies of my father property/ court case/follow up with interest and gradually my brother has acquire all the property in his name OR his wife name OR he must have sold i never intefere in this matter but after that my brother started harassing my mother because now he wants my mother's Flat in his name and my mother's wish is to grant the house to both the daughter has not got any thing of his husband share ( all the brother has got the equal share) from my father. Looking to this situation of my brother behavior my mother has decided that before dieing my wish is that i will this flat to my both the daughter and she wants to make the will. Secondly my brother's are harassing to my mother and saying that to sign the dcouments other wise we will stop giving the expenses and saying that tell your daughter to look after you because my mother is not signing any documents we have clearly given the instruction to my mother that don't sign any dcouments without we see & inform to us that why my brother are rudely behavior with my mother and giving slang to my mother and un necessarily harassing now a days my mother became more sick because of my brother's behavior. Perhaps if my mother dies before my father then who will get this property? can my mother can prepared the will in my both daughter name then there is a problem ? if any body from the family members can take the objection after my mothers make the will and registerd ? please advice can we both daughter's can send the warning Notice/legal notice to my brother for the precaution of my mother's property. in this situation can you guide us how we can take the action against my brother. please guide us