Rights of property

Sir, we have sold our Ancestors property in Goa (North) for some reason, In the inventory process the house was in my grandfather name who had 5 children's (3) sons & (2) daughter's, after my grandfather died in the inventory process my GF transferred the house in my Father names & his (2) brother's which is highlighting in the ( I & XIV ) form. Both the daughters names r not mentioned.as they were married, Now both my uncles were ( batholor's ) & after their death made a will stating all movable & inmovable property will stand in my Father names.. After my parent death we did the Succession Certificate at the Sub-Registar in Canacona Goa South, (5) legal heirs (brother & sisters) & my 2 uncles names (batchelor). As per the I& XIV form, Now Firstly the buyers lawyers is saying that the Succession Cert is invalid n that all the names should be included that of my Aunty also in the Succission Cert, Secondly my Aunty who r dead, their children's r now claiming for their rights of their share, so my question is , Is the Succession Cert invalid & can my Aunty children's claim their share even thou my Aunty names not mentioned in the I&XIV form .in this matter my father was taking care of the property n that all taxes were paid by my father's, my Aunty children's were not taking care but claiming for their share. Kindly help. Thank you