How do I redirect new user creation to come under the site for my supdermin?

I am using Flexmarket. How do I redirect new user creation to come under the vib.in site for my superadmin profile, Suradmin?

They come under the Network admin, I want it under the site admin of Vib.in. That way I can restrict the sub-admins under Vib.in. Please let me know, thanks!