We pick i.root-servers.net, one of the 13 root servers (1), and ask it about tj and learn that tj is delegated to four name servers (2), so we ask phloem.uoregon.edu and get the following answer:
Tj (the tld of Tajikistan) is a domain controlled by four domain name servers at ripe.net, uoregon.edu, tojikiston.com and nic.tj having a total of six IP numbers. All six of them are on different IP networks.
The two name servers ns and ns2.tojikiston.com together
Six of the seven domains that use the two name servers ns and ns2.tojikiston.com together, hereafter referred to as "name server group 1", point only to the IP number 193.111.11.3 (example: kuvatova.tj, abg.tj and dhl.tj ).
The name server ns2.tojikiston.com
There are about twenty domains that use the name server ns2.tojikiston.com.