MTB resistance is characterised by a low spontaneous mutation rate. (ex: ~2.6 INH-specific mutation occurs per 10 MTB bacteria per generation) The conventional understanding of the development of resistance is that sequential drug resistance evolves through fragmented therapy, leading to the killing of susceptible bacterial populations and enabling the proliferation of drug-resistant populations, that can be fuelled by several programmatic and socioeconomic factors. Sputum sample from presumptive DR-TB cases are collected in sterile Falcon tube after thorough rinsing of oral cavity with clean water. Sputum sample along with form containing details of patient like Name, Age, Sex, Address, Type of family, HIV status and name of hospital are documented and sent to NTEP lab. Samples were used to perform AFB, CBNAAT, FL-LPA. CULTURE/DST is performed in patients whose sputum test results showed discrepancy in CBNAAT and LPA. 241(96.4%) cases were pulmonary DR-TB, while remaining 9(3.6%) were extra-pulmonary cases. But all of the extra-pulmonary cases found to be sputum microscopy positive.