Long term capital gain

I am planning to sell a property where market value is 10 times the govt value for registration. Nobody is coming forward to buy if I am insisting on getting complete amount through check. I am ready to pay 20% tax. Buyers are reluctant as either they don't want to pay 7% stamp duty or have inability to pay by check or both. Is there a way I can still disclose the income and honestly pay 20% tax and be clean from my side? I don't want to be harassed by AO treating it as income from other source and taxing at 30% or add penalities with some weird acts.