Aravindan Sivasamy (Jayam Ravi) is a 26-year-old youth who was brought up in an ashram run by Harichandra (Nassar). The atmosphere that he grew taught him high moral values, disciplines, dignity, devotion, etc. But when he comes out of the place, his belief and learning will be questioned by the cancerous system. It unsettles him and make him fight against the immoral cultures of the society. He decides to take on corrupt bureaucrats and his friend Ramachandran (Soori), a lawyer Raja Chandrapandian (Subbu Panchu), a journalist Gopinath (C. Gopinath), along with his girlfriend Poomaari (Amala Paul), join him in his mission to fight against the corruption.
They form a plan and successfully expose 147 government officials, including a court judge and an MP, and are caught taking bribes for Unknown person by the name of Hari Chandran, which was created by non-other than Aravindhan himself using his own picture, but modified to look different. Now, all those corrupted officials team up to take on Aravindan and his team with a look-alike who fits the image and description of Hari Chandran, named Narasimha Reddy (Jayam Ravi), a 42-year-old middle-aged man who does underground work for the Andhra Pradesh government with hints of him being a womanizer; to showcase that Hari Chandran is indeed a real person, as a method of thwarting Aravindan's battle.
Narasimha Reddy, who resides in Andhra Pradesh, accepts the deal with the government officials with the condition of the corrupt officials giving him 14.7 crores to seal the deal. Fearing that all his efforts will go in vain, Aravindan heads to Andhra Pradesh to thwart Narasimha Reddy from claiming the false identity of Hari Chandran, leading to a fight between the two. As the case takes place in the court, Aravindan and his team members are dejected due to Narasimha Reddy claiming himself as Hari Chandran.
When the 147 corrupt officials are happy that things are going as planned, the plot twist occurs where Narasimha Reddy states the truth, indicating that he was supporting Aravindan from the start after all. The court declares in favor of Aravindan and Narasimha Reddy praises Aravindan for his effort. Narasimha Reddy further explains who exactly he is, as he is a person who runs orphanages and senior homes for female children and elders. He explains that he used the 14.7 crores he received from the corrupt officials to build orphanages in 4 separate states.
As both Aravindan and Narasimha Reddy embrace each other and step out of the court, Narasimha Reddy is stabbed multiple times and a fight breaks out, as the henchmen are set up by the corrupt officials to kill both Aravindan and Narasimha Reddy. Both Aravindan and Narasimha Reddy, with the help of the public, fight the battle, where Narasimha Reddy saves Aravindan from being stabbed, but Narasimha Reddy eventually succumbs to his injuries from further wounds, leaving Aravindan and his team devastated. The end credits showcase that Aravindan and his team become successful in their fight against corruption.
Jayam Ravi was signed for the lead role. He would be doing a dual role, a 26 years old young man and a 42-year-old man. Nayantara was the first choice for the role. Due to date issue Nayanthara turned down the offer and Amala Paul signed for the role, who would play the female lead in both the versions. Meghana Raj was said to have an important role in the film, but she said on Twitter that she was not acting in the film. Ragini Dwivedi was roped in to play an important role.
The first schedule has been wrapped after it was shot in the scenic locales of Chalakudy and Goa. The team started a long and hectic schedule from November 20, 2012. The movie had many interesting sets like a cupboard opens up to a dummy printing press done by art director Jacki.
The music was composed by G. V. Prakash Kumar uniting for the first time with Samuthirakani. The soundtrack was released on December 11, 2013. Directors Ameer, S P Jhananathan, Rajesh, Sasikumar, Gautham Menon, Pandiraj, Suseenthiran, Vetrimaaran and Cheran along with actors Arya, Nani were present at the launch. Two songs and a trailer were screened at the event. Indiaglitz called the album a "mixed package", Behindwoods described it as "tasteful blend of melodies", Cinemalead rated the album 2 stars out of 5, saying that it musically failed to stand up.
The satellite rights of the film were sold to Sun TV. The film was given a "U" certificate by the Indian Censor Board. Producer KS Sreenivasan was initially planning to release the film by late January 2014. It was scheduled to release on February 14, 2014, but was postponed to March 7, 2014. However, it was again pushed by one day. The film had run into financial problems and after Jayam Ravi's father Editor Mohan sorted out the issues, theatres started screening the film from March 8 evening.
Nimirndhu Nil received mixed reviews. Baradwaj Rangan wrote, "Movies usually end with messages, but director Samuthirakani begins with one — and thereon, the film is just one well-meaning exhortation after another. The screenplay, sometimes, feels less a collection of dialogues and emotional cues than a series of op-ed pieces sewn together in the most stentorian fashion". The Times of India gave 2 stars out of 5 and wrote, "The(se) scenes (in the first half) have a swiftness that keeps things from turning dull while camouflaging the flaws. The dialogue too is witty and sharp...and strikes a chord, igniting righteous anger in us. Sadly, that is short-lived as the film soon does a spectacular nose-dive...And, the director sacrifices sense for scale and makes serious episodes seem like farce while turning the intended funny ones less amusing". Sify wrote "Nimirinthu Nil works in bits and pieces with a terrific first half which slows down post interval. The director had worked his script up to the interval point, but falters in the second half as he thrusts too many commercial elements. Still it is a watchable entertainer". Oneindia.in gave 2.5 stars out of 5 and wrote, "Nimirnthu Nil, which could have been an wonderful affair, turns out to be an average film in the end". Behindwoods.com gave 2.5 stars stating it as "a vigilante movie which could be given a shot".