Form 26QB related payment in Installments or Lumpsum

I'm buying an under-construction flat above 50L.. So far I have paid 9% of Total flat cost to builder and 90% will be arranged through Home loan.. The builder is insisting I pay the 1% TDS on the TOTAL Flat cost which I have already paid in Form 26QB.. But there is a column in the form regarding "Amount already paid/credited currently" in which I have mentioned the 9% value paid in actual so far. However builder is asking me to revise this 9% to 100% of flat cost under column "Amount already paid/credited currently". This is so that builder can claim entire 1% in one-go. My question is, is it ok to do that? Because in actual I have not paid 100% moreover I need to go for bank loan for rest of the amount disbursement. What is the suggested way forward (since I have already paid 1% of total flat cost as Challan): 1. Revise amount paid to total flat cost in Form 26QB instead of 9% 2. Modify Form for installment type payment instead of lumpsum payment option as selected. 3. Withdraw form 26QB, request for refund and file fresh form 26QB. 4. Any other option