1. It has to be seen whether the procurement has happened after OC or the entry in 2A has appeared after the OC date.
The date of entry in 2A is not relevant if the procurement has happened and the invoice is dated prior to OC. In such case, the ITC will have to be proportioned and availed to the extent of the carpet area of the units sold on which GST is liable.
If the procurement is made after OC, assuming OC is received after 01.04.2019, it would advisable to reverse the credit proportionately as discussed above.