The BBC reported Bachchan will play gambler Meyer Wolfsheim in the latest retelling of F. Scott Fitzgerald's 1920s-era New York romance.
Luhrmann has begun shooting the film in Australia with Leonardo DiCaprio playing the title role.
"Over the years, Amitabh's films have made a tremendous impression on my life and work. His film 'Sholay' was my introduction to Indian cinema," the BBC quoted Luhrmann as telling Indo-Asian News Service in an e-mail interview.
Bachchan, 68, has appeared in more than 180 Indian films throughout his 40-year career.