Necro never had spells at level 6 in Classic/Kunark/Velious.
Edited: thought I'd give a bit more details:
http://lucy.allakhazam.com/spellhist...41&source=Live shows this was changed from a level 8 spell to a level 6 in 2005 (logged in Lucy on 2005-05-09 19:12). Before this point:
- INT casters had new pells at the following levels: 1, 4, 8, 12, 16, 20, 24
- WIS casters has spells at level 1, 5, 9, 14, 19, 24
From this point both received spells at 29, 34, 39, 44, 49 then every level onward up to 60 (level 50 with Velious, level 51+ for Kunark).