A chronicle of the life of Indian boxer Mary Kom, who went through several hardships before audaciously accomplishing her ultimate dream.

Jassi Randhawa (Ajay Devgan) is an unemployed good-for-nothing man who receives a letter from the Punjab government about buying his property in Punjab. To sell the property, Jassi leaves for Punjab. On the train, he meets and falls in love with Sukhmeet (Sonakshi Sinha). In Punjab, Jassi accidentally meets Billu (Sanjay Dutt) and, seeing he is new to the area, Billu invites Jassi to his home, where he treats Jassi like a god. There, Jassi realises that Billu is Sukhmeet's brother. Soon enough, it is revealed that Billu is Balwinder Singh and Jassi is short for Jaswinder. However, Billu's family has to follow one Punjabi rule: A guest in the house should never be harmed. Now, Billu must wait for Jassi to leave the house to kill him. Jassi learns about it and comes up with a hilarious plan to foil Billu's shenanigans.