India's Electricity sector has experienced substantial transformation in recent years, propelled by a range of policy initiatives designed to foster competition, enhance efficiency, and boost the contribution of renewable energy sources within the country's overall energy portfolio. The study evaluates the relative efficiency of electricity generation utilities in 19 unbundled state-owned electricity generating utilities in India using Data Envelopment Analysis (DEA). The current investigation aims to conduct an extensive evaluation of the relative efficiency of 19 unbundled state-owned electricity generation utilities to identify inefficient generation utilities, peers, targets, DMU summary, besides providing helpful insights for intended improvements using CCR model with a constant return to scale over the years of academic years 2019–2020, 2020–2021, 2021–2022. The results include performance efficiency, gaps in inputs and outputs of inefficient utilities. Also, a peer-to-peer comparison of inefficient and efficient utilities is provided. Based on these results, inefficient utilities can develop strategic plans to improve performance.