Family Settlement Deed

My Grand parents, have 4 sons and 4 daughters, of which 1 of my aunt is dead. My Grandfather Purchase a land in my grand Mother's name in 1965, while registering the document their is a mention that my grandmother purchased this land through streedhan. in the 1st week of Sep-1993 my grandparents, my father and his 3 brothers made a notarized, (with book entry number) Family settlement deed dividing the property in 3 parts, 1 portion of my grand parents, 2nd and 3rd portion between 4 brothers, In Aug-1993 time my 4 aunts have given a notarized(with book entry) no objection certificate for the property to be given for development and they will not raise a claim or have any objection in the same. In September ending using the family settlement deed we have submitted the property for urban land ceiling, and got them mutated and entered our names on municipality records and have been paying the taxes for the same. Now in oct they signed 2 Power of attorney (POA) to the builder for development purpose. 1st POA by 6 members (grand parents and 4 sons) and 2nd POA between grand parents and my builder to the extent of mutated property. In 2000 the builder wanted to start a hospital and he approached my grand parents to provided the property for guarantoship, only my grandparents signed the guarantoship agreement not my uncles, in 2003 they bank got bankrupt and the builder did not pay the loan amount, he put a collateral of 54acres of land. In 2004 a govt officer was appointed as liquidator and sold of the 53 acres of land for an amount of 49laks, which we feel that they sold of the property for more than 4 crores, but showing on 49laks, secondly they came to our apartment for impounding and auction of the property, we approached the city civil court and got a stay. We have fighting the case stating that the property settlement deed was made, Urban Land celilings was made and declared and mutation was done, so we said that since the property was mutated and divided, we did not sign the guaratorship and made a statement that the whole agreement was made by builder(who has duped couple more banks) was to cheat us in convenance with the bank, now the liquidator does not have any supporting documents like the project of the hospital, feasibility of the loan, reason for the loan and other documents and they do not have the loan agreement papers as well. everything was goig smooth.in 2016, my aunts approached the court asking requting to nullify theFamily settlement deed and demand their share, last week the court gave a judment stating that the Family settlement deed in not acceptable as evidience since not registered, and my grand mother is the sole owner of the property and is not a benami property,no siblings would get any share and directing the liquidators to recover their money. Can we challange the judgement and if yes is their any hope of we sons getting the property.