Service tax on flat registration after oc

Hello, I booked flat on 29-SEP-2015 in Pune and done registration on 26-Nov-2015, below is the case for that I want to know about the service tax payble or not 

 [ Flat Base cost is 49,40,000/- , Service Tax - 1,72,900/- Vat - 49,400, 20% DownPayment - 9,88,000 ]

1. Booked falt on 29-Sep-2015 with booking amount [ 1,00,000/- (One lac) ]
2. Builder received OC Certificate on 10-NOV-2015 - this builder was not communicated 
3. Made all remainging payment (20%) for registration on 16-Nov-2015 [Service Tax: 1,72,900  + Vat - 49,400 + DownPayment - 8,88,000 + booking Amount + Registration Charges ]
4. Complted flat registration on 26-Nov-2015

So in this case what will be Service Tax...
1. Will Service Tax applicable only on the Booking Amount as OC is recevied before Registration also other payments done after getting OC.
2. Will Service Tax applicable on the Flat base Cost as booking is done on before getting OC?

Thanks