From some evidences we can get from the 3 entrance of RoE, I think that Mark 06 it's (Not) Just an Evangelion.
1. In 1.0 the Base of Taghba, on the Moon, is also refered As "Site of Extraction". So, the Mark 06 (Covered with NGE's Lilith Mask... Creepy) is Not just being created there, but it seems that was FOUND in there.

2. In 2.0 we discovered that in the Rebuild timeline there are FOUR Adams. We also found that the SEELE is doing something "unusual" with the Mark 06, who's refered as "The TRUE Evangelion, who's going to make faith to Lilith's Pact." Fuyutzuki also reveals that SEELE wants to make an Impact with this Mark 06, stating that "they want to use a REAL GOD".

3. In 3.0, we find out that Eva 13 is one of the survived Adams, so making one of them like an Eva it's Not that complicated. Also, Mark 09, a basical copy of Mark 06, has got some powers that makes it look like a Divinity, in fact is referred as "Adam's Vessel" by Mari.

In conclusion, for me Mark 06 was an Adam, survived on the Moon and that used by SEELE to make an Impact between 2.0 and 3.0. What do you think?

I mean there's this theory: https://wiki.evageeks.org/Theory_and_Analysis:Identity_of_the_Adams

There's also been a great deal of discussion about the vessel of Adam part and how that might indicate that it's not an actual Adam in various threads of Reichu's theories, although I don't exactly remember the exact details