Unemployed Rana is not getting a job. He stays in the same room with his friend Dildar. Dildar takes him to his master. With the permission of Ustad Kalu Khan, he started stealing people's wallets. Dildar trained him in the pickpocketing. But after he is caught, he goes to Peter Saxena. Peter invites him to join his smuggling. Rana responds and goes to see Peter in his office. But Kalu's man sees it and informs Kalu. Kalu threatens Rana. Rana conspires with Peter and calls Kalu to a garden house and kills him.
Peter introduces him to the buyers of his diamond business and sends him to Thailand. In Thailand, Peter's men welcomed him. There he met a semi-Bengali semi-Thai Linda. Linda shows him around Thailand. In the meantime, his relationship with Linda became closer. But he has to return to Bangladesh. He has to go back to Kathmandu, Nepal. There, Peter's business friend went to Joshi's hotel. When Shila, Joshi's assistant, leaked all the details of their business to him, Rana persuaded Joshi to do the same. Joshi calls Peter away from Bangladesh and at one stage of the argument, Joshi is shot by Peter. When Rana chased him, Joshi fell down the hill and died.
Rana returned to Bangladesh and proposed marriage to the receptionist Rehana. Although Rehana was reluctant at first, she agreed considering Rana's finances. But the next day he learns that Rana has actually avenged his previous insults. After the death of Kalu Khan, Dildar wants to work under him. The two were planning to make a film when singer Yasmin Khan was caught stealing her jewelry. Yasmin tells them to leave town. This is how his life continues to deceive people.
Film critic Rahman Moti praised the creativity in directing the film and the acting of Bulbul Ahmed. According to him, love, deception, conscience all make Mahanayak a complete film.[5]
