As per the case facts, writ petitions were filed challenging the constitutionality of Section 10(26AAA) of the Income Tax Act, specifically its definition of "Sikkimese" which excluded Indians settled in ... Sikkim before its merger, and the proviso which excluded Sikkimese women marrying non-Sikkimese men after a certain date, leading to the Supreme Court's intervention. The question arose whether Section 10(26AAA) and its proviso are unconstitutional for excluding certain categories of individuals from income tax exemption, particularly those domiciled in Sikkim before its merger and Sikkimese women marrying non-Sikkimese men. Finally, the Supreme Court directed Parliament to amend the Explanation to Section 10(26AAA) to extend exemption to all Indian citizens domiciled in Sikkim on or before April 26, 1975, to prevent unconstitutionality and ensure parity. Until amendment, individuals not in the Register of Sikkim Subjects but domiciled on or before the specified date are entitled to the benefit. The proviso excluding Sikkimese women marrying non-Sikkimese men after April 1, 2008, was struck down as ultra vires Articles 14, 15, and 21.