On 15 January 2026, a two-judge bench — Justice R. Mahadevan in the principal opinion, with Justice J.B. Pardiwala concurring — held that the General Anti-Avoidance Rule in Chapter X-A of the *Income-tax Act, 1961* applies to any arrangement yielding a tax benefit on or after 1 April 2017, even for pre-2017 investments structured to claim Mauritius treaty benefits. The Tax Residency Certificate, the Court held, remains a relevant factor but is no longer conclusive for GAAR purposes; the *Azadi Bachao Andolan* line on TRC-as-conclusive-evidence is substantially modified. A digest of the holding, the 2016 Protocol grandfathering architecture, and the practitioner fallout that has emerged through May-June 2026.