That login page is for Enom registry rocket which provides limited functionality in managing your domains. Either contact the person to create custom nameservers for you or ask him to issue a new domain management URL with functionality to create nameservers.
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If so, as previously stated you can switch to custom nameservers and enter them in via the user interface on access.enom.com.
If the name servers are not registered you can register them via enom.com. http://www.enom.com/domains/RegNameServer.asp
(On menu under 'Domains'->Advanced Tools->register a name server)
I believe that the only one who can register the name servers is the person who has them in their enom account.
If zahid has given you access to manage the domains through access.enom.com, he would be the one to setup the nameservers for you.... an alternative plan is for him to create a sub-account for you and push the domains into it.... at which time you could login to enom.com and register the nameservers yourself.