Rambo (also marketed as Rambo: The Undefeatable) is a 2025 Indian Tamil-language romantic sports action drama film written and directed by M. Muthaiah and produced by Kalanithi Maran under the banner of Sun Entertainment. The film stars Arulnithi in the titular role, alongside Tanya Ravichandran, VTV Ganesh, Abhirami and Ranjith Sajeev (in his Tamil debut).
The film was officially announced in October 2025. It has music composed by Ghibran Vaibodha, cinematography handled by R. D. Rajasekhar and editing by Venkat Raajen.
Rambo was released directly on the streaming service Sun NXT on 10 October 2025.
Gowtham, a ruthless heir to a vast education empire, and Ram, a compassionate orphanage caretaker, grow up with starkly contrasting values. When Malar uncovers Gowtham's hidden dark secret, it ignites a fierce clash between the two men a brutal battle of strength and will.
The music and background score is composed by Ghibran Vaibodha, in his second collaboration with Arulnithi and M. Muthaiah after Dejavu (2022) and Kutti Puli (2013). The audio rights were acquired by Sun Entertainment. The first single titled "Mayakkam Enna" was released on 7 October 2025. The second single titled "Girra Girrara" was released on 11 October 2025, after the film's release. The entire soundtrack album was released on 15 October 2025, after the film's release.
Rambo was directly released via the streaming service Sun NXT on 10 October 2025. The film had its television premiere on Sun TV on 20 October 2025.
Rambo received negative reviews.
Charishma Tatiparthi of Big TV rated the film 2.25/5 and wrote, "An earnest boxing drama with heart, but not enough heat to win the bout." Anusha Sundar of OTTPlay rated the film 1.5/5 stars and wrote, "It tries to blend kickboxing with drama but ends up tangled in illogical writing and weak storytelling. Despite flashes of humor, the film fails to land a solid punch emotionally". A critic from Cinema Vikatan gave the film a negative review, criticising the story for its lack of novelty and the screenplay for having predictable twists.
Suhas Sistu of The Hans India wrote, "Marketed as a gritty tale with kickboxing at its core, the film falls flat due to lazy writing, illogical situations, and painfully weak characterisation." Johnson of Puthiya Thalaimurai called it bland, criticising the boxing scenes as forced and included merely to justify the film's title.