The assessee-company is  in the business of development of real estate. It followed the mercantile system of accounting. During relevant year assessee commenced a project of development and construction of building and received certain advance from the prospective buyers of the flat. The  assessee had offered the income only in respect of the flat owners with whom agreement to sell had been entered into. AO  held that entering into an agreement and its registration was not necessary for recognition or revenue on advances or on the completed part of the project. Observing that said condition has been dispensed with in cases falling under AS-9, the AO made addition to income shown by assessee. CIT (A) confirmed said addition. On appeal the Tribunal held that as regards the immovable property is not conveyed by delivery of possession, but by a duly registered deed; it is date of execution of registered document, not the date of delivery of possession or the date of registration of document which is relevant; once the executed documents are registered, the transfer will take place on the date of execution of documents and not on date of registration of documents. Followed, Alapati Venkataramaiah v. CIT (1965) 57 ITR 185 (SC)  Matter remanded.   As regards method of accounting the Tribunal held that, where assessee, engaged in business of real estate development, offered income in respect of sale of flats to flat owners with whom agreement to sell had been entered into, AO was to be directed to bring said income to tax on basis of percentage completion method having regard to principles of AS-9. (AY. 2009 -10 to 2012 -13).