Is Notarized Family settlement deed along with Patta (not registered) be used in sale of property ?

My late Great Grandfather bought a piece of land of 780 Gaz. and got it registered. After his demise, his two sons, divided the property among themselves in the ratio of 56:44 through Family settlement deed signed in presence of two witnesses and duly notarized. The original Patta of the property is with my Grandfather's brother's sons and copy of which is with my Grandfather. Now can my Grandfather sale his share of property without solely..? If yes, would the signature of his deceased brother's sons would be required ? Any other consideration to be kept in mind ? please advise