Hard to say, with only one picture (especially that one). If I had to "guess", I'd say he was a healthy 2yr old.
I'm not familiar with New York deer but that buck looks like he will be 3 celebrating his 3rd birthday soon. Have any pics with horns?
I said 2yr old....because that's what he is, now. We're saying the same thing. He'll be a 2.5, this fall.