You have a choice between What time is it? and What's the time? Both of those are equally correct. 'What time is this?' isn't right. The only time you'd hear this would be as a rhetorical question. If someone arrives late, the angry person who has been waiting for them might say it. But the answer expected would be an apology or explanation - not the actual hours and minutes!

What time is it

In my opinion, The correct is : What time is it?