I'm very sure that your question is wrong.
You cannot ask "I or he".
You should ask "I/he or me/him".
In my opinion you should go for I, he, she, you, they, etc.
Who's next?
He.
Next round:
Who's next?
I.
You ask for a subject.
Maybe me is possible too, but I'm not sure.
**Neither a teacher nor a native speaker.**
Cheers!
"I am" or "he is".In the question "Who's next ?" what's the correct answer : "Me/I" or "He" ?