To setup the child nameservers, you should have the Reseller account. If you have the reseller account and want to setup your own nameservers then you can follow the below mentioned steps:
1. Login to HELM Control Panel
2. Click on System Settings icon.
3. Click on Servers icon.
4. Select the machine name where the DNS server is configured.
5. Select the DNS services from the Service section.
6. Click on Add New button.
7. Enter the Nameservers on first section and select the IP from another section.
8. Click on Save button.
Accuwebhosting.com
1. Login to HELM Control Panel
2. Click on System Settings icon.
3. Click on Servers icon.
4. Select the machine name where the DNS server is configured.
5. Select the DNS services from the Service section.
6. Click on Add New button.
7. Enter the Nameservers on first section and select the IP from another section.
8. Click on Save button.
Accuwebhosting.com