This tutorial assumes you have a domain name registered through register.com and starts from their homepage.

Now we’ll learn how to register private nameservers or custom nameservers.

Creating or registering private nameservers must be done with the domain registry where the domain name resides. To create, for example, ns1.youtdomain.com here, the domain yourdomain.com must be at this REGISTRY.

Click the LOGIN tab at the top of the screen. Scroll down.

Enter your USERNAME and PASSWORD in the boxes provided, then click LOG IN.            

You are now logged in to your account.

Click on the domain name you wish to use to create private nameservers.

Click on the link to MANAGE REGISTERED NAMESERVERS. Scroll down.

Enter the new domain server in the DNS SERVER box under the REGISTER DNS SERVER section.

Now enter the new nameservers associated IP ADDRES in  the provided box. The IP address should have been provided to you by your webhost.

Click the CONTINUE button to have the new nameserver created.

When finished creating the nameserver, you’ll have to REPEAT the process to register your second name server. Registering private name servers, requires you to register TWO SEPARATE NAMESERVERS (i.e.: ns1 and ns2) each with its own unique IP Address.

Remember that after you submit your new nameservers and IP Addresses to the registry, IT CAN TAKE 24-48 HOUR for the new nameservers to propagate after you make these DNS changes.

How to create a private Nameserver at Register