Twenty-eight popular paddy varieties released and notified throughout India between 1976 and 2015 were molecularly characterized using SSR markers. The lab analysis was conducted at the Biotechnology Laboratory, Faculty of Agriculture, Annamalai University and stability study over three locations under the Cauvery Delta region during December 2022 to May 2023. The results showed that nine SSR primers were polymorphic and PIC values varied from 0.363 to 0.551, while the marker RM 118 had the highest PIC value (0.551). The range of the detected heterozygosity was 0.304 to 0.622. Neis’ genetic distance created the dendrogram, which divided the varieties into seven clusters. According to Neis’ genetic measure, variety G8 (ADT 39) from cluster I and G15 (TKM 9) from cluster VII confirmed the degree of genetic diversity among the varieties studied. From molecular genetic diversity, nine high-yielding varieties were chosen based on grain yield per plant and subjected to stability analysis in three different environments. Significant genotype × environment interaction was observed for all the characters; hence, these varieties' stability was assessed. Variety, G9 (ADT 48) showed non-significant S2di and regression coefficient value around unity with high mean for days to first flowering, grain length and grain yield per plant and plotted under group I in genotype grouping technique. Varieties viz., G8 (ADT 37), G9 (ADT 48), G15 (TKM 9) and G16 (MDU 6) are the most stable and acceptable for both favourable and unfavourable environments. It showed stability factor around unity for grain yield per plant and they will be selected as parents to develop stress-tolerant varieties.