"Badla," released in 2019 and directed by Sujoy Ghosh, was a commercial success at the box office. Starring Amitabh Bachchan and Taapsee Pannu, the film received positive reviews for its gripping storyline and performances. It grossed over ₹138 crore worldwide against a budget of around ₹30 crore, making it a hit. The film is a neo-noir thriller that keeps the audience engaged with its twists and turns, contributing to its favorable reception.

"Badla" is based on the Spanish film "The Invisible Guest" (original title: "Contratiempo"), directed by Oriol Paulo. The Hindi thriller, directed by Sujoy Ghosh, follows a successful businesswoman who is accused of murder and seeks the help of a lawyer to uncover the truth. The film incorporates elements of mystery and suspense, mirroring the intricate plot twists found in its Spanish counterpart.

No, "Badla" is not a remake of "Evaru." "Badla," released in 2019, is a Hindi film directed by Sujoy Ghosh and is an official adaptation of the Spanish film "The Invisible Guest" ("Contratiempo"). On the other hand, "Evaru," released in 2019, is a Telugu film directed by Venkat Ramji, inspired by the same Spanish film. While both films share a common source, "Badla" and "Evaru" are distinct adaptations with different narratives and styles.

In the movie "Badla," the killer is revealed to be Naina Sethi, played by Taapsee Pannu. Throughout the film, Naina is accused of murdering her lover, and the story unfolds through a series of flashbacks and revelations during her meetings with her lawyer, Badal Gupta, portrayed by Amitabh Bachchan. Ultimately, it is disclosed that she killed her lover in self-defense, but she manipulates the situation to protect herself and frame someone else for the crime. The film explores themes of betrayal, revenge, and the complexities of truth.