Dear Sir, My mother sold the residential flat that she partly inherited from her mother along with my aunt sometime on 27th September 2014. She invested the proceeds in an under construction residential flat located in an apartment project in November 2014 (full upfront payment covering the gain amount). At that time she signed what is called Agreement to sell/construction agreement with the builder. The apartment at that time was just in the process of foundation setting up. As of today, the basic structure is complete and tiling on the insides is being done. It was supposed to be ready in Dec 2016 but might go on until Mar 2017. Technically, (as per Section 54) she should register before 25th September this year to be within the 2 year period or 3 years if under-construction. I suppose my question is: does she have to register the flat before the end of two years of sale of her inherited residential apartment OR does she have a provision of another year of extension since it's "under construction" OR is that the provision of the extra year of (2+1) applies only when one is building an individual house on a plot ?. Please advise. Thank you.