Hey Bro is an action musical comedy that revolves around Gopi (Ganesh Acharya), a carefree oversized villager, who lives with his grandfather. Gopi discovers that he has a twin brother who lives in Mumbai with their mother, so he decides to go to Mumbai to meet them. On reaching Mumbai, he finally meets his brother Shiv (Maninder Singh), who is head of Mumbai Police Station. After meeting Shiv, Gopi realizes that he and his twin brother are poles apart. However, will the situation play out in reuniting the brothers?