Mother Property Distribution Legally

I want legal Distribution of my mother property my father is no more and my younger sister and his husband has Converted My Mother Mindset In Wrong Manner And Changed Everything And Also They Have Changed Everything With Their Name we are 2 sisters as per my knowledge my mother have only one property as of now of her name and some deposits as per my knowledge I want a legal distribution of my mother property as my father told me orally that this property and whole distribution will on your name but I do not have any legal paper proof and my husband and me are very honest and I am trustworthy we never think of such things we want a way so that we can proof and take distribution of property in my name please suggest me what to do