18% GST payable on Civil contract services to IIT Madras

In re ESVEE Constructions (GST AAR Tamilnadu) What is the applicable rate of tax under CGST Rules for the Civil Contract Services (SAC 995414) undertaken / to be undertaken to our customer M/s IIT, Madras (GST No.33AAAAI3615GlZ6) by us with effect from 01.01.2022 by virtue of amendment to Notification No. 11/2017 C.T (Rate) vide Notification No.15/2021 C.T (Rate) dated 18.11.2021? Whether it is 12% or 18%? The Civil contract services of the applicant provided / to be provided to IIT Madras is covered under serial number 3 (xii) of Notification No. 11/2017 C.T (Rate) dated 28.06.2017, as amende...