Hi Srikar,
in a BOL entity of a search result like BTQRSrvCon, all attributes are set to read only, so you can not change them with SET_PROPERTY_AS_STRING.
To set the support team for display purpouses only, please redefine the GET_* method of your context node attribute of your search (for example GET_SERVICE_TEAM) and write your coding there.
If you want to change the data of the ticket, you have to get the BOL intance of the ticket from the BOL entity of the search result with GET_RELATED_ENTITY and process from there.
Best Regards,
Christoph