Just for your information: as the title says, I want to confirm that level 6 spells are available on BG1EE.
Having said so, getting that is really specific:
* First I removed the level cap. There is a thread on this forum about how to do that
* I was soloing.
* I was soloing as a sorcerer.
To be clear: I didn't find any level 6 scroll on BG1EE. But as probably you know, on some of your level ups, sorcerer can chose to learn new spells among all the available spells At level 12, sorcerer can choose one from the 6th level spells.
PS: before someone asks how I deal with traps. There are also threads on this forum talking about that. Basically you deal with it, usually receiving damage. Mirror image helps a lot, summons not so much. And yes, it makes Durlag Tower a hell. For me killing the demon at the last level, or the other demon when you are back to Ulgoth's Beard were easy compared to deal to all the traps at the tower. But the rest of the game is not so trap-problematic.