Kartavya (1979) ~ Action Classic ~ Hindi Movie

Forest officer, Vijay Rai, is sent down by the Central government to Madavan jungles, and is tasked with combating poachers and smugglers. His commitment to his job leads him to expose the criminal activities of Dhanpat Rai - who in reality is Diwan Singh and may be responsible for killing his dad as well as separating him from his brother, Ajay - now known as Dushyant and is an equal partner in Dhanpat's criminal empire.