First of all it is very clear that you do not understand law but insist a reply in your taste which is not legally maintainable.
Understand the things in the following lines properly"
The self acquired property of your great grandfather fell into the hands of your grandfather by the operation of a testamentary Will reported to have been executed by the testator and there upon the beneficiary sold the property to some third person as an absolute owner. The only person who had rights to object the genuineness of the Will was his sibling, i.e., your grandaunt. She never raised objections then nor till this date, therefore the execution of sale of the property acquired through operation of a Will has been admitted by the person who was the only survivor to your great grandfather to protest or make any objections to i, if any. Even otherwise she cannot object to the sale of entire property, she was entitled to only half the share in it. Therefore if she has a claim for half a share in the property, it is deemed to be an oral partition between them which clearly extinguished the term called 'ancestral'
The children of your grandfather cannot claim a share out of the share in the property that was sold by your grandfather because they do not constitute as coparceners. Thus if they are not entitled to claim a share in it, the next generation, i.e., you and your siblings sadly are not entitled to any share out of your father's so called share which was not there.
The Will whether forgery or fake cannot be disputed by you at this stage because it was enforced in the year 1989 and at that time the only person who should have objected was your grand aunt who has not done it till date and it is very badly barred by limitation.
Therefore in my opinion, you do not have anything to claim in the by gone history of the property that was owned by your great grand father which was sold by his son and legal heir very long back even when it had not acquired its ancestral status.
Do not expect lawyers to give a misleading reply just to appease you or suiting to your taste and wrong understanding of law or misinterpreting it.