Rights of Daughter when property owned by father is disposed by fraud

Last year my father passed away suddenly, he didn’t sale his property or he didn’t make will. After 1 year of his demise, my brother and mother told me that his property is disposed of and they are not telling me anything else. However I am confident that he didn’t make will or he didn’t sold it because my father told me about it before his demise and he was also aware of my brother and mother. After my father’s demise my brother took my sign on WAKALATNAMA also he has all the property documents. Now question arises that how my mother and brother can prepare documents for disposal of my father’s property? I am sure that they have made fake documents. I am my father’s younger daughter now 22 years. No family member or relative helping me. . In this situation what should I do and how? How serious it is for me? Please suggest.