Which is correct between these two sentences?

Question

Context:

1: Who the hell he is? 2: Who the hell is he?

I have come across both of them and both of them are spoken frequently, so which is correct grammatically?

Answer 1

1: Who the hell he is?

is not a question. It is a clause that probably wouldn't stand alone. You could use it like this:

I don't care who the hell he is.

2: is correct as written.