The Central Board of Indirect Taxes and Customs (CBIC) has issued a notification giving real estate companies a one-time option to choose either of the tax rates. "Provided that in case of ongoing project, the registered person shall exercise one time option ... to pay central tax on construction of apartments in a project at the rates as specified .... by the 10th of May, 2019," the CBIC said.

from Times of India https://timesofindia.indiatimes.com/business/india-business/realtors-have-time-till-may-10-to-opt-for-old-gst-rates/articleshow/68688795.cms