Structure and Accessibility of Indian Research Institution Repositories: A Comparative Analysis Based on Indexed Repositories in Open Doar

India has emerged as a significant contributor through its network of Institutional Repositories (IRs) within the global Open Science landscape. The present study provides a multidimensional analysis of the structural frameworks and accessibility metrics of premier Indian IRs registered in the OpenDOAR (Directory of Open Access Repositories). The IRs have become essential for preserving and sharing scholarly outputs with the increasing demand for open access (OA) knowledge dissemination. This study evaluates the technical architectural standards, metadata health, and accessibility coefficient of the repositories of the Council of Scientific and Industrial Research (CSIR), the Indian Institutes of Technology (IITs), the Indian Institute of Science (IISc), etc., with an impact on the One Nation One Subscription (ONOS) model. The study also examines strengths, gaps and areas for improvement and offers recommendations to enhance the accessibility and global visibility of Indian research outputs. As per the key findings, metadata quality strongly influences accessibility: low metadata health leads to information invisibility and structural improvements can enhance accessibility. The study concluded that India has achieved significant structural scale, but the transition toward full-text open access is still inhibited to some extent by institutional policy differences.