The film opens in medias res where street fighting issues are raised in Mumbai. Sports chairman Peter Braganza (Kiran Kumar) expresses his desire of making street fighting a legal sport and decides to open a league called Right 2 Fight (R2F). Meanwhile, imprisoned Garson "Gary" Fernandes (Jackie Shroff), a recovering alcoholic and former MMA expert under rehabilitation, is released from his jail term and his younger son Monty (Sidharth Malhotra) comes to pick him up. Monty gets tensed when his father asks about his elder son David and takes him away to their home. At home Gary acts protective of all the belongings of his wife Maria, who died many years ago. David (Akshay Kumar), now a physics teacher, has a daughter with kidney ailment. Unable to arrange money from the bank and other sources he earns money through street fights. This stresses out his wife Jenny (Jacqueline Fernandez) as she is worried about David. Meanwhile, Gary, who misses his wife Maria (Shefali Shah), starts hallucinating about her. Gary then tries to meet David but the latter ends up throwing Monty and Gary out of his house in rage.

Monty is then revealed to be Gary's illegitimate child. Maria nevertheless loved Monty, as she did David. The two brothers had a close, loving relationship until David was 18 and Monty was 15. On the night of Monty's 15th birthday, Gary came home drunk and apologizes to Maria for destroying the family, but mentions his lover Sarah's name, instead of Maria's. An enraged Maria confronts Gary about this. In a drunken state Gary hits Maria who is injured and dies. A furious David pushes Gary aside. When Monty comes close to Maria, David angrily pushes him away, holding his father and half-brother equally responsible for his mother's death. This creates a rift between Gary, Monty and David.

David later loses his job in the school when the principal Shobhit Desai (Kulbhushan Kharbanda) learn's about David's involvement in street fights. Monty, who wants to be a fighter, is then introduced to Suleiman Pasha (Ashutosh Rana), a fight agent. Suleiman fixes a match with Mustafa in which Monty is defeated. This enrages Gary but Monty has a rematch with Mustafa, where Monty defeats Mustafa and is declared a selected fighter for R2F by Peter. The fight is recorded and uploaded to YouTube and soon Monty becomes an internet sensation. Monty undergoes training to become the R2F champion. Meanwhile, David too decides to be a full-time fighter and Jenny encourages him to do so. Suleiman trains David and arranges a match while Monty celebrates his victory at a bar. David soon is victorious in the fight. R2F soon becomes a sensation and fighters from all over the world show their interest in the league. Eventually, brothers David and Monty make it to the finals.

Gary, feeling guilty leaves the arena. During the fight, David breaks Monty's shoulder. Gary rushes towards David and apologises for his mistake and tells David not to release his anger towards his brother