Agrement Which is on white paper

Hi sir/ Madam I am ravali (age 23 marrief) my father was already dead i am only one child. My elder father n young father, Grand father n Grand Mother n my mother all r alive 3familys sit aroung including grand parents under witness and finally decided for sharing properties. Finally the aggrement was settled and written on white paper We all r signed including grand parents and 6 witness on 5/6/2016 Now grand mother and younger father not comming in frent of witnesses for providing bounderies. They tolding now after grand parents death we can share. But we find that younger father registered some properties before the agrement. Quetions: 1. If i file any legal case on my younger father? 2. The white paper agrement will legally challenged or agre the court? 3. If my mother have any legal support from the law to share my father share? 4.If law support us to shar my grand parents propery in future if they registered total property to my young father? 5. If there is any chance to occupy my properties noticed in agrement if there is any legal issues?