My father abandoned me and my mother during her pregnancy. After that we are living in my mother's h

My father abandoned me and my mother during her pregnancy. After that we are living in my mother's home under partial care of her relatives and my father. But when i was 8 years old, from a local police station he declared that he divorced my mother and from police station he gave some papers as proof of divorce attested by our local lawyers and my mother gave a sign in a white paper. The content of the paper was that 'me and my daughter never come to you for any share and properties and to disturb you' but i was only 8 years old at that time and i am not bothered and i don't know anything about at that time. Now i am 19 years old and also i am not ready to abandon my shares and rights in my father's properties. Have my mother's signed proof have any value in this situation ? Will i get my share from my father's properties.