• Payment of TDS for real estate purchase

Recently I have booked a flat in Kolkata. It is jointly owned by me and my wife. As the consideration amount is above 50 lacs, thus I need to pay TDS for this purchase. We will be paying the property cost in installments for next 3 years. 

Do we require to pay TDS for each installments ? or should pay TDS for whole amount ? 

I have paid the first installment on 2nd week of April,2015. What is the due date to pay TDS ? 

As , me and my wife (single income source) are the joint owners, Do we require to submit separate form 26QB  for filing TDS ?