CLI: 

> set snmp mib
        -contact <string>
        -location <string>
        -name <string>

GUI:

Navigate to Configuration > System > SNMP. In the right-hand pane, Click the "Change SNMP MIB" link.

This article describes a SNMP fundamental configuration, to set the value of the following OIDs on NetScaler.

• sysContact: OID:1.3.6.1.2.1.1.4
• sysName: OID:1.3.6.1.2.1.1.5
• sysLocation: OID:1.3.6.1.2.1.1.6