If you wish to know how to check your name servers (NS) for your domain, you may follow this guide.
For example your domain is google.co.id.
Go to either https://who.is/ or https://whois.domaintools.com/ to check your domain details.
Now type your own domin, and then hit enter, or click magnifier icon.
The results will displayed below.
As you can see above, the Name Servers (NS) for domain google.co.id is :
ns1.google.com , ns2.google.com ns3.google.com and ns4.google.com.
You will also have some informations such are expire date of domain as well the registrar informations. If you need some domains, you can go to Exabytes Domain.