On robes how can I make it so only darkside or lightside can wear it ?
When you've got the item editor open, click Properties, then double click on the bottom (empty) space and then on Property Name scroll down to Alignment limitation... then you can change it to Light, Dark, or Neutral...
Was that with the K-gff or ERF Edit
I opened it with Kotor Tool and then yeah, so I haven't a clue...
I would use k-GFF editor, but the editor that comes with KT works fine. If you want an easier on to use, use the one in Kotor tool.