If someone wants a .LY TLD (top level domain) or .IO TLD, how do I determine which domain registrar (e.g., GoDaddy, Register.com) supports the purchasing of this TLD?

Does anyone know a regular expression to match Domain.CCTLD? I don't want subdomains, only the "atomic domain". For example, docs.google.com doesn't get matched, but google.com does. However, this ...