It depends... Maroon 5's DWK has been hanging around the top 10 thanks to massive airplay. Is it a hit? I'd say a moderate one with a higher than deserved peak.
Generally, yes but the song doesn't have to peak in the top ten to be a hit.
Alessia Cara is a perfect example, I hear Scars to Your Beauitful every five minutes on the radio in Chicago and it's only peaked at #12 so far but I would definitely consider it a hit.
Cool for the Summer peaked at #11, that was a hit.