TDS-jointly owned

My mother and father both have separate business incomes and they are filing IT returns every year.They both want to buy a property jointly.Total sale value is 56 lakhs.They both want to transfer money to sellers in 50:50 ratio.Even sellers inherited that property jointly.we assume that the share of the individual is less than 50lakhs,so we won't liable to cut TDS.But Sub registrar saying that,even you are buying jointly;you are registering this property in a single document and not registering separately.So you have to cut 1% TDS in sale value.Is this version correct or not?Experts here,plz reply.