You will not be able to use the standard VLAN tool and Flexview in NetSight with the Extreme switches. This is included in NetSight OneView 6.3 and higher.
Detail information is available from the NetSight help. Click on the Search All Topics button to the lower left within the NetSight Help docs. A search field will be presented in the upper left. Enter in the following :
How to Create and Edit a VLAN
Item number 6 should be "How to Create and Edit a VLAN"
You can get basic VLAN information using the FlexViews from the following location: Flexviews > XOS >XOS VLAN. The process is displayed below.
1. To change Flexviews, to to typical Flexview tab labeled "Interface Summary"
2. Click on the floppy disk Icon and Open
3. Choose XOS VLAN
4. From here, you can typically get VLAN info using the 'Play' button, but may not be able to edit these values.