Khanna made her debut with the 2013 Indian political spy thriller film Madras Cafe where she played the role of Ruby Singh, the wife of an Indian intelligence officer Vikram Singh portrayed by John Abraham.[8] She had to undergo acting workshops before taking up the role.[9] The film—particularly the story and direction—impressed most Indian critics.[10] Reviewing the film, Saibal Chatterjee of NDTV stated that Khanna "makes an impact in a brief but significant appearance".
