"What does he do?"
Translation:वह क्या करता है?
This would be more 'What work does he do', while the above sentence doesn't necessarily imply we are talking about work.
I understand the literal translation but, in English, the above sentence does normally mean 'what work does he do'? As in what's his job?
Both the English sentence 'What does he do' and the Hindi sentence 'वह क्या करता है' have the idiomatic meaning 'what work does he do'.
So, your translation should have been accepted.
To be very pedantic, I can think up some instances where the two wouldn't be fully equivalent. For example:
"He is always bothering me."
"Oh yeah, what does he do?"
But I agree this is a bit nuanced, and it would be fair to accept both translations.