"My students are Muslims, Catholics, and Hindus."
Translation:Siswa-siswa saya ada yang beragama Islam, Katolik, dan Hindu.
Indonesian is mainly a subject-prominent language, but sometimes topic-comment sentences like this crop up.
So "Siswa-siswa saya" is the topic, and the rest is the comment, which is a sentence on its own. "Ada yang" is the subject, and the rest is the predicate. A more literal English translation would be:
"As for my students, some are Muslims, (some are) Christians, and (some are) Hindus."
What about these sentences:
Material ini fungsinya untuk melindungi kepala.
The function of this material is to protect the head.
As for this material, it's function is to protect the head.<--?
Putri Salju kulitnya putih seperti salju.
Snow White's skin is white as snow.
As for Snow White, her skin is as white as snow.<--?
If you want the English sentence to follow the structure of the Indonesian sentence, you are correct. This is useful when you're learning a language to see how it works.
But of course, in the practice of translation, you don't always have to follow the structure of the original sentence. Producing a sentence that sounds most natural in the target language is important too.