Advances in CRISPR/Cas9 Gene Editing Technology, its applications and Immunotherapy in India: A Review Short running title: CRISPR/Cas9 Gene Editing Technology, its applications and Immunotherapy

*BACKGROUND* This review explores CRISPR/Cas9 gene editing, detailing its mechanism and broad applications. It covers bacterial genome modifications and significant clinical advancements, including its role in cancer immunotherapy (e.g., CAR-T cells, viral targeting) and treating genetic blood disorders. Recent innovations like Prime Editing and advanced delivery methods are highlighted. The review also examines CRISPR's status and challenges in India, noting regulatory gaps despite progress in diagnostic tool development. It concludes by emphasizing the need for continued innovation, ethical guidelines, and robust regulation to fully realize CRISPR's potential amidst ongoing technical hurdles. *Methodology* This comprehensive narrative review synthesized information from a targeted search of scientific literature across databases like PubMed, Scopus, and Google Scholar, using specific keywords to identify advancements, applications, and the Indian context of CRISPR/Cas9 gene editing. Information was then critically analyzed and organized thematically. *Results:* The review extensively explores the significant clinical advancements achieved through CRISPR/Cas9, including its pivotal role in cancer immunotherapy—specifically in developing chimeric antigen receptor T (CAR-T) cells and targeting oncogenic viral infections (HBV, EBV, HPV, JCV)—and its noted potential in treating hereditary blood disorders like sickle cell anemia and β-thalassemia. Recent technological innovations, such as Prime Editing (PE) and Prime Editing and Template Integration (PASTE) for precise insertions, the application of catalytically inactive dCas9 (CRISPRi/a) for gene regulation, and various advanced delivery systems, are also discussed as key outcomes of ongoing research and development. Furthermore, the analysis of CRISPR's status in India highlights progress in developing diagnostic tools for infectious diseases (e.g., Tata MD CHECK SARS-CoV-2 Kit 1.0, FELUDA) and improvements in Cas9 enzyme engineering. *Conclusion * CRISPR/Cas9 is a revolutionary gene-editing tool with transformative potential across bacterial engineering and diverse clinical therapies, including cancer immunotherapy and genetic disorder treatment. Despite remarkable advances, persistent challenges like off-target effects, delivery hurdles, and, specifically in India, the urgent need for clear ethical and regulatory frameworks, must be addressed. Realizing CRISPR's full benefits demands continued scientific innovation alongside responsible ethical guidance and robust policy development.