Bosses at the Kannada Film Producers' Association placed the ban on the Saroja star after reports emerged alleging she has ruined the "domestic harmony of a fellow actor" by becoming romantically involved with married star Darshan.
The move came after Darshan was arrested in southern India on suspicion of domestic violence following a complaint from his wife Vijaylakshmi.
She later withdrew her complaint, but the dispute was reportedly about his relationship with Thukral.
The actress has vehemently denied the allegations and has labelled the movie ban "ridiculous", complaining she has never been consulted about her version of events.
Kannada Film Producers' Association president Munirathnam Naidu tells the BBC, "If Nikhita (Thukral) apologises for her behaviour and says she will just work in films and not get involved in domestic affairs of fellow actors, we will withdraw the ban."
But Thukral argues, "There's nothing between us beyond a professional relationship. If Darshan has a problem with his wife, how am I responsible?"
Heads at the association say the star is free to challenge the ban.