Division of ancestors land.

Sir, My grandfather and my grandfather's brother both used to own ancestral property of 18 acres. My grandfather's brother died unmarried without leaving any heir. Before death my grandfather transfers 2 acres of ancestral land in the name of elder brother of my father. My grandfather had only 2 sons; my father and his elder brother. My father had died 30 years back before the death of my grandfather who has died 25 years back. Elder brother of my father had died too 10 years back. Presently, physically me and my siblings owns 7 acres of land out of total 18 acres of ancestral land which was originally owned by our grandfather and his brother. Please explain that: 1. Is it legally possible for grandfather to transfer 2 acres of land in name of his elder son without the consent of my father. 2. Is the present division of ancestral land between the alive legal heirs right. 3. Would it be beneficial to make any legal advance in the case as the land is worth crores at present. Thanks