Would such property be divided equally among all sons?

Hi, the scenario is father have one son from first wife and two sons from second wife. now son from first wife wants to buy a plot and he asks his father to finance it. father agrees and pays complete amount of plot and plot is registered on son's name. Now son starts building a house on that plot and here as well father helps him and son from first wife and his family lives there. Father has another house where he lives with two sons and wife. after some days father dies. now at the time of division of property the son from first wife claims equal share in property where father used to live with second wife and two sons.two sons agrees and give him equal share. Son from first wife also states that the house which is financed by father belongs to him only as its registered on his name and cant be divided. Now my question is 1. House where son from first wife lives can be considered for equal division among all sons? 2. House which is financed by father there is no direct proof of it that its financed by father so can we ask for investigation and prove its financed by father by verifying payslips of son from first wife?