Employees of Tata Iron & Steel Co. Ltd. (TISCO) challenged the 2001 amendment to Rule 3 of the Income Tax Rules, 1962, which changed how the taxable value of housing ... provided by employers was calculated. They argued the new rule, which used fixed percentages of salary instead of "fair rental value," was inconsistent with the Income Tax Act, which requires a "concession" in rent for it to be considered a taxable perquisite, and that it unfairly discriminated against non-government employees in violation of Article 14 of the Constitution