TDS on Immovable property

Year 2014: Apartment booked with builder on Construction Linked Payment Plan.

Consideration Amount of Property on Agreement = 49 Lacs. TDS not paid on any installment as consideration value is less than 50 lacs.

Year 2020: Possession of apartment offered.

Builder sends final invoice with increased super floor area, New Consideration Amount = 52 Lacs.

Will TDS be applicable now? Is it to be paid on only 52-50 = 2 lacs or on complete 52 lacs.

Is any penalty / interest applicable in TDS.