Click the "Search by feature" link, and in the new browser window click the "S" link. On the left sub-window (Features available) single-click to select "SNMP Version 3", click "Add" button to move "SNMP Version 3" into the "Features selected" sub-window. Click "continue". In the next display select the applicable platform, release, and feature set, and you will find whether your IOS based Catalyst switches support SNMP V3.
