When set to Wireless Repeater mode, the Wireless Repeater is able to communicate with a remote access point within its range and retransmit its signal. Click Site Survey to select the access point that will have its signal repeated by this Access Poi...

Please upgrade your WLC to the latest version 7.6 or above. Hope this will resolve your issue.

Please refer to the links-http://sbkb.cisco.com/CiscoSB/GetArticle.aspx?docid=a51a7ab259e4403ea147508f247e5946_configuration_of_wireless_settings_in_802_11b_g_mode.xml&pid=2&converted=0http://sbkb.cisco.com/CiscoSB/ukp.aspx?pid=2&vw=1&articleid=2201

Please refer to the doc that will be helpful to resolve your query-https://supportforums.cisco.com/document/9879166/cisco-mobility-services-engine-mse-unable-discover-clients-and-rogues