You can add users with the web GUI configuration utility or at the NetScaler command prompt
In the web GUI navigate to System > User Administration > Users, and create the user.
Logon to the NetScaler and run the following command from the NetScaler command prompt add system user, enter a password, and confirm.
add system user Enter password: Confirm password:
Note: additional parameters can be configured with add system user command see the reference document.
Logon to the NetScaler and run the following command from the NetScaler command prompt set system user nsroot
set system user nsroot