In 2012, Devaiah appeared in Vivek Agnihotri's erotic thriller Hate Story, produced by Vikram Bhatt, co-starring Paoli Dam. This was his first film where he appeared in the lead role, where he portrayed the antagonistic role of Siddharth Dhanrajgir, a cocky son of a rich Business tycoon, who involves in a black-business. The film went to become a sleeper hit, and garnered the positive reviews from the critics. Taran Adarsh of Bollywood Hungama rated 3/5 to the film and labelled devaiah's performance as "excellent". Same year, he played in Vasan Bala's crime thriller film Peddlers alongside Nimrat Kaur, where he portrayed the role of Ranjit D'souza, a 20-years old boy, who gets trapped in the drug trade. The film was premiered at the Cannes Film Festival, which was muted by the critics. In 2013, Devaiah appeared in Sanjay Leela Bhansali's romantic-tragedy drama film Ram-Leela, starring Ranveer Singh and Deepika Padukone, where he played the negative role of Bhavani, which was a 'blockbuster' in the year. After a year gap, In 2015, Devaiah appeared in Harshavardan Kulkarni's adult comedy film Hunterrr, co-starring Radhika Apte, where he portrayed the role of Mandar Ponkshe, a sex-addict guy and describing his lustful journey in life. The film did well at the box-office. In 2016, he was also seen playing the role of an NRI in Vivek Agnihotri's film Junooniyat, co-starring Pulkit Samrat and Yami Gautam in the lead roles.