The 29-year-old, along with Nissan India, is searching for 20 contestants. The aspirants can join the talent hunt competition, which starts Oct 19, by uploading a short clip of themselves.
The 20 winners, who will be selected by online voting, will appear alongside Ranbir in the movie.
"I'm incredibly excited to be involved in this ground-breaking movie with Nissan - no-one has attempted anything like this before. Speaking to all Bollywood fans out there, this is your once in a lifetime opportunity to join me in the magic of the movies.
I'm looking forward to seeing your auditions and can't wait to meet my co-stars, so get dancing, get voting and get involved," Ranbir said in a statement.
The finalist will also get a chance to produce the movie, choose its music, work on the wardrobe and name the characters.
"New Star of India" will be premiered in various cities across India in January next year.