What tax liability are you referring to here.?
There is no GST payable for ready to move-in flats.
Currently, EMIs for ready-to-move-in apartments do not attract indirect tax. But installments paid to the builder for an under-construction property attracts a service tax of 15 percent on which abatement is provided. The premise here is that a builder is providing a service to a homebuyer by constructing an apartment. The abatement is allowed to take care of the value of the land involved in the construction of apartments,
Property for which completion certificate has been issued: No GST is applicable on ready-to-move-in or completed property as per the CGST Act, 2017.
Under Construction property when part consideration has been paid to the builder: The buyers are liable to pay 4.5% service tax applicable on the invoices raised or consideration paid before the July 1, 2017. However, payment made by the buyer to the builder on or after July 1, 2017 against invoices issued on or after July 1, 2017 shall attract GST at the rate of 12%.
Under construction property when entire consideration paid to the builder before GST rollout: There is no GST payable on such property even if the construction is completed after July 1 2017. This transaction will attract service tax at the rate of 4.5% because as for the point of taxation rules, 2011, the transaction attracts service tax and not GST.