If you are a Master /Alpha / Super Reseller you need to follow this.
make sure your Reseller client creates his/her private nameservers at their registrar and then points the domain to our IPs.
If you have already made a new RESELLER account for a new client, go into "WHM/ZamFoo: Master Reseller/admin functions/make nameservers" and add them to the reseller account you select, do not type in any names, just select the account in question, add in the RESELLER client email address and click "Create them" never do this for standard cPanel accounts only reseller accounts.
Now you need to add "A" records so we have nice clean DNS:
Go into WHM/DNS functions/Edit DNS zone
Go to Add New Entries Below this Line
In the first box enter NS1 click on "Select" and then select "A" record, now add in the IP address in the last box as found in several places above
Repeat in the second box for NS2 but do not add the same IP address, it is almost the same except change the last digit to one digit higher
Click on Save.