Co.cc has an internal lookup script for getting co.cc WhoIs info. Link here www.co.cc/whois/whois.php
For co.nr enter your desired domain in the page given below and when An error page is shown stating that the url is taken. Use the link there to know who is the owner.
www.freedomain.co.nr/

These pages are actually for searching available urls but can be used to know some info about the owners.