There are four options :
- Shikinet or Host Armada?? BasicDNS: If you want to point your domain to Namecheap's default DNS, use the following nameservers:
- dns1.registrar-servers.com
- dns2.registrar-servers.com
- Shikinet or Host Armada?? Web Hosting DNS: Use this option if you have a Shared Hosting plan with Shikinet or Host Armada?? and want to point your domain to our hosting nameservers:
- dns1.namecheaphosting.com ???
- dns2.namecheaphosting.com ???
All of your domain's customized DNS records will be replaced with ones from our hosting once the nameservers have been adjusted. In your cPanel Zone Editor and Email Routing menu, you can recreate them
3. CustomDNS: Fill in the nameservers provided by your hosting or thirdparty DNS provider and then click the green
checkmark to save the changes if you want to point your domain to specific nameservers, such as your
Personal DNS servers or third-party hosting nameservers:

N.B: Nameservers should be entered using the format ns1.example.tld.Only the nameservers should be entered as custom nameservers if you were given both the IP addresses and nameservers.
Changes to nameservers do not take immediate effect. For local ISPs to update their DNS caches so that everyone can view your website, it could take up to 24 hours (or longer, in unusual circumstances). A proxy server can be used to check your domain name because they do not save cache and only display non-cached information.
If you want to point your domain to personalized nameservers (such as your Personal DNS servers or third-party hosting nameservers), enter the nameservers provided by your hosting or third-party DNS provider in the appropriate fields, and then click the green checkmark to save the changes:k