ChromatiCraft, also a Reika Mod, btw way too laggy to play alongside GT6, like NEI being unavailable due to lagspikes kinda laggy.
RotaryCraft is slightly compatible with GT6, I did a lot of Stuff to make HSLA work with GT6 without letting GT6 be able to create HSLA so you have to make Reikas Blast Furnace sooner or later.