Source of money for purchase of plots 1000 sq yards value of 3.2crore

one of my uncle purchasing the plot of 1000 sq yard with SRO prize is sq yrd 32000 total purchase value is coming nearly 32000000( three crore rupees) he has never filed any ITR he has to file ITR now for showing the above income as his ITR for showing the source of income what are the ways income can be shown, he has paid 10 yrs back to seller amount for above 1000 sq yrds  plot, as each sq yrd 8000 wise total value he paid was 80lacs in cash for seller, meanwhile it went to court on litigation, resulted recently from Court plot value as per SUb registrar also four times increased by Govt, now he wants to do register his name of 1000 sq yrds with present value of Rs.32000000/- future income tax dept will raise query asking the source of income, what is the source of income can be shown, he is having agri land only 2acres that too paddy grown only and last three years his bank statements transactions aslo value of Rs.80lacs only, kindly show me ways to show his source of income for filing ITR of Rs.32000000.