Tax exemption cap limits central GST to a lower rate for eligible research institutions subject to certification and usage conditions. The notification exempts specified scientific and technical goods supplied to eligible research and medical institutions from central tax exceeding an amount calculated at a low fixed rate, subject to conditions including institutional certification by an authorised officer or the head of the institution, requirement that goods be used for research purposes, additional no-objection certification for live animals, a prototype aggregate value cap, and a post-installation non-transfer period for certain institutions.