Seeds of local cultivar Sorghum (Shweni-15) were treated with doses (0Gy- 800Gy) from Gamma ray 60Co source. The objective was to study the genetic variability of induced mutation for the improvement of local cultivar Sorghum in M2 generation. The lethal dose 50% (LD-50) value for Sorghum (Shweni-15) was found in 830Gy. The agronomic traits of heritability (h2) genotypic coefficient of variation (GCV), phenotypic coefficient of variation (PCV) and genetic advance of mean (GAM) were studied in M2 generation. The traits like plant height, stem width and seed yield per plant exhibited high heritability accompanied with high GAM in the treatment with 300Gy. The treatment with 300 Gy also showed moderate heritability with low GAM was observed for number of leaves per plant, brix % and 100 seed weight. The treatment with 400Gy had high heritability with high GAM for stalk weight and moderate heritability with low GAM for panicle width and branches per panicle. In this study, gamma radiation induced wide variation with the treatment of 300Gyand 400Gy in most of the traits in Sorghum (Shweni-15).