My grandfather bought a property of 6 marla in 1975 in Lahore. He has 6 sons. Apart from two (my father and another son) all took other properties from my grandfather and left the house. Only two left in the house. In 2010, my tayabu (the other son) sold his share(3 marla). In 2020, my father got a Dastbardri document from all other sons and sisters that they withdraw from the remaining 3 marla. in 2021 my father sold the property.
Now the question is, will Gain Tax apply on us? Because this is not a case of buying the property. It was Dastbardari/Inherited.
I don’t understand your case fully but there are zero inheritance/gift taxes in Pakistan. If the property is inherited, you pay no tax at all on it. In fact, nowhere in the world is gains tax paid on inherited property.