Hi. You can know the date of delivery of possession as informed by builder to RERA, from the website of RERA itself. Just feed in the project RERA registration number and you will get all the details about the disclosures made by the builder to the RERA authority regarding the project. You must insists for a RERA agreeement to be registered in your name by the builder if you have made payment of 10% or more than 10% of the sale consideration to the builder. The builder has to disclose the date of delivery of possession in such agreement registered in your name and has to deliver the possession of the apartment by the specified date. If the builder does not hand over possession by the date specified in your agreement then provided you wish to continue with the project you can claim interest at statutory rate from the stipulated date of possession as mentioned in your agreement till actual possession is given to you. If you do not wish to continue in the project then you can claim the refund of entire sale consideration alongwith statutory interest from the builder under RERA.