He is best known for his roles in Cube Zero, as Ryjkin, and in the films Land of the Dead, Assault on Precinct 13 and The Sentinel.
At only eleven years of age, he made his first film called Boy with a Violin.
After completing high school, he studied drama at the University of Sarajevo's Academy of Dramatic Arts, taught by professor Boro Stjepanović and world-renowned director Emir Kusturica.
By the second year of the four-year-long academic program, Geljo started getting principal roles in film, television, and theatre in the former Yugoslavia.
Geljo is also known for his roles as Mima Šiš and Roki Mokroguz in the famous Yugoslav and Bosnian show Audicija.