Capital Gains exemption u/s 54F

Mr. Sanghai had sold a commercial property, which was a long term asset and invested the same in purchase and construction of a flat in a apartment in Mumbai, within the one year of sale of asset and claimed deduction u/s 54F of income tax act, but later the builder has not completed the possession of the apartment within 3 years and the apartment remained under construction even after 3 years. The period of 3 years is lapsed without any mistake of Mr. Sanghai Now? Full Article