Don(1978)

Original title: डॉन

A ruthless gangster named Don is killed during a scuffle with the police. Since only DSP D'Silva knows of this incident, he recruits Vijay, who is a spitting image of Don, to replace the original Don and infiltrate his gang. D'Silva plans to nab the entire gang, but when he dies during a raid, the secret that Vijay is not Don is also buried with him.