They haven't officially debuted yet. NCT-U is just a sub-unit that is released first before the official debut.
That's why NCT comes up with 'Topic' not 'Singer' if you look up their name in searching engine.
-That's why NCT is labeled as 'Topic' while NCT-U is labeled as 'Singer'..
-They haven't officially debuted yet?
-Hul.. I didn't know this..
-I knew this..
-Hul.. I even fought with my friends over NCT and NCT-U..
-It's so fascinating.. I hope they will officially debut soon!
-Ah, that's why they are called NCT-U..
-Please debut them soon.. My wallet is ready..
-I'm a fan but this is my first time hearing that NCT is labeled as 'Topic'ㅋㅋㅋㅋ
-There are some members who are currently waiting for their official debut, Youngho-ya, let's debut!
-How many members are there in NCT-U?
-There's a song that was sung by 5 members, and the other song was sung by 3 members. There are 6 members who are already revealed by now.
-I really don't know what kind of group is NCT..
-I'm looking forward to NCTㅠㅠㅠㅠ
-Then how many members are going to debut in NCT?
-No one knows.. Only SM does..
-It hasn't been decided yet!