That is a good question to which I too would like an answer!
Notwithstanding the fact that he made the rep teams as correctly stated by SoM, Clay would probably be 18 and if so it is my understanding an election has to be made (i.e. play u/18 for NSW making him ineligible for NZ representation (i.e Junior Kiwis and so forth).
Some guidance please! Anybody?
While I'm not sure his election he is definitely eligible having been in NSW for a number of years. I remember seeing Zac Clay represent St Clair in the penrith comp in under 13s. As a matter of interest Tepai Moeroa was in the same team. Therefore he is eligible to represent NSW under the new eligibility rules.