Ancestral property rights and unregistered partition deed

Partition of ancestral property between my grandparents namely 1 , 2 & 3 is made in the year 1977 through an unregistered partition deed and all the property was mutated to their names as per the deed. Among all the property one of the property was purchased in the name of grandparent 3 in the year 1967 (purchased 10 years before the partition done) with joint family money. This particular property was equally shared to grandparent 2 & 3 during partition and the same is mutated to both as per the partition deed and all the land records are in our names(I am the grandson of grandparent 2)as per the deed. Now the son of grandparent 3 has filed a case in the court that this full property belongs to them and we have done the forgery and mutated this property to our name. He has taken a temporary injunction stating that the land shall not be alienated till the hearing of the court. We are growing eucalyptus trees in that land and already harvested the trees for 4 times till now. When we were cutting the trees in the land he objected for the same and filed a case in the police station that we have scolded him when he objected for cutting the trees. Grandparent 3 and his son have sold some of the lands which were given to them in the partition deed and during selling they have stated in the sale deed that those properties were their ancestral properties and the date of partition deed is also stated in that. My question is -Is he having any rights on the land since the partition deed is unregistered. -When the temporary injunction is there stating that the property shall not be alienated cant’t we harvest/ cultivate the land. what does the word "shall not alienate" means. -Since they have mentioned the sale deed date in the property which they have sold can it be considered that the partition is valid.