Vat applicability on sale of immovable property

Yes it is a deemed sale. That means the transfer of property of goods in execution of works contract.

Say for Eg. if a dealer is in activity of construction of Building, he will consume all raw material i.e. Cement, steel etc in construction of building.

Since the cement and steel is getting consumed in construction of building, builder will not pay VAT. Hence, department concern is correct. You will have to pay Works Contract Tax as per the provision of Karnataka VAT Act.

I am not doing any construction works of buildings . I am only undertaking works contract from IOCL. I sold my building because of financial problem that too fully completed building. I have not made any agreement prior to contruction