It appears the film was produced in three languages:

https://www.themoviedb.org/movie/191453-l-atlantide
https://www.themoviedb.org/movie/3474-die-herrin-von-atlantis
https://www.themoviedb.org/movie/113630-the-mistress-of-atlantis

https://www.imdb.com/title/tt9731436
https://www.imdb.com/title/tt0023002/
https://www.imdb.com/title/tt9731440/

But I can't tell which one is the original.

found this (In the remake of 1932, Georg Wilhelm Pabst directed what Molodezhnaja said: "Pabst did not just shoot his own version, but three of them!" It was not uncommon to stage not only the German version but also a foreign version for France "L'Atlantide" and for America "The Mistress of Atlantis" (Figure 1), both cast with a different male lead, but the female star remained the same for all: Brigitte Helm.) here https://atlantisforschung.de/index.php?title=Die_Herrin_von_Atlantis they have all different cast so I don't know if they are duplicates? I would say the original is the german one, Papst did the others with different casts I think he couldn't do this at the same time?

Thanks @Samara. We should only keep one though:

Multiple-language versions?
Content filmed simultaneously in two or more languages (e.g. Tamil and Telugu) should be added as one entry. The tricky part is to figure out which version is the original version."

Even if the cast is different? We will lose the information here about the other actors and their parts or should we add them to the original cast?

@Samara Yes, the cast if frequently a bit different. But the other versions will eventually be added as alternative versions on the main entry.