GST clarifications on penal charges, payment aggregators, skilling services, and reverse charge regularisation under the state tax framework. GST clarifications cover the tax treatment of penal charges, payment aggregator settlement services, research and development services against grants, NSDC-approved skilling services, reverse charge on commercial property rent under composition levy, and incidental services of electricity utilities. Penal charges levied by regulated entities for non-compliance with loan terms are not liable to GST, while RBI-regulated payment aggregators are treated as acquiring banks only for the limited settlement exemption and not for payment gateway services. The circular also regularises GST for specified intervening periods on an 'as is where is' basis.