1. Then you login your server and click my accout and choose domain option and lunch you domain when your domain list come then you click on which domain you want to make nameserver like ns1.example.com and ns2.example.com.
2. When you click your domain open a dailog box now you serach host summary option in dialog box.
3. Now click and new host summary again dialog box come and set here your host ns1 and fill your IP address give in your panel.
4. Again repeat this process for ns2 host summary.
5. Now you can set your DNS record and fill your created DNS like ns1.example.com and ns2.example.com.