Ancestral property undivided property

Hello Ajay/Respected lawyers I had posted a few things before on our property at wilson garden.we have collected documentary evidence. Now here is what the documents say,this property belonged to my great grand dad. My great grand dad has received a certain share of money to purchase this property from his father.Release deed is being done by my great grand dads father in lieu of money received. Now is this completely ancestral?,I have found that income tax has acquired the property based on premptive sale undervaluation and have acquired the property dold it through auction. The sale deed done from income tax to the party who had purchased it from auction says it has been acquired on basis of will and one place says it is succession. My grand dad has created the will like done by my great grand dad and will has no partitions mentioned.The will is fabricated,and signature is a massive difference. I hope this is completely ancestral none of the generations have witnessed the transaction.And now how should we go about??How can income tax dispose an ancestral property. And the entire property has been disposed on basis of a will without taking signatures of the majors my dad,dads brothers,sisters and my grand aunt living to this day. please assist please explain how to go about