This Blu-ray will include both the theatrical (149 mins) and director's (209 mins) cuts. The Extended Cut, which is actually the German mini-series, is what the editorial states that this is. And it is not. That cut is 293 mins long and is only available as of yet on DVD. hope this helps!
Just to clarify, Disc 1 of the Blu-ray contains the original 1981 cinema version (149 minutes), whilst Disc 2 contains the Director's Cut cinema version (209 minutes). It does NOT contain the original 6-part TV mini-series, either as six episodes, NOR as one gigantic length movie. If you want the TV series, you'll have to get that on DVD!