Nock is not unfamiliar with the black jersey, having represented the country in the New Zealand School's side in 2014 that played in a tri-nations series with Fiji and Australia.
He was also part of the NZ side that took part in the Oceania Under-20 rugby tournament in the Gold Coast last month.
The side won one and lost one game against Australia.
Nock started the match they won and came off the bench in the second match.
He said Gold Coast was a good experience and he intended to up the ante during the global showpiece in Manchester.
"I guess it's a good opportunity for us as a team to promote ourselves, particularly those who haven't signed for any Super Rugby side to play well and get selected for a Super Rugby side," Nock said.
He relayed the news of his selection to his family and friends and said he has made them proud.
The NZ U20 squad assembles in Mt Maunganui on May 27 ahead of a game against the Chiefs' Development side three days later.
Robertson said the coaching team was confident their squad offered skillsets and versatility that provided both experience and fresh fire power.
He expects competition to be fierce at the World Championship with England likely to again be strong, and Australia also providing stiff competition with the availability of Super Rugby players.
"We're in a tough pool. We've got Wales who won the Six Nations and Ireland who performed really well. We've also got Georgia - they're new to the competition, after they won the tier two competition to come up and we know they love to scrum and maul and they are big men as well."
