The Soviet vehicle IS-6 will appear in-game in the future, but you can already make your judgments of how profitable and reliable the tank will be owing to the article appeared on the game portal.
As usual apart from the historical reference you will also find players’ opinions:
“murgen[UNC]: Even though IS-6 is quite an interesting machine, with it being a tier 9 it'll have to be pulled on the globe with the same amount of effort as the second pantera. It would be fairly good as a tier 8 heavy tank, or even a tier 8 premium tankas a counterpart to the Lowe, but not beyond that. The game lacks the very famous and massively produced T-10, also known as the IS-8, and this one would really fit into tier 9, so I don't think the developers made the right choice.”
The point of view of the developers is presented by Petr Bitiukov aka Tiger, game-dev and top tank-man:
“GoHa.Ru: Unfortunately, this machine was barely faster than the IS-4 – only 35 km/h, in spite of it’s visuals suggesting it’s a quicker machine. How fast and maneuverable IS-6 will really be?
Tiger: The final parameters have yet to be decided, based on results acquired from testing, but IS-6’s maximum speed will likely to be no different from it’s historical 35 km/h. Even though the specific power of “Object 252” was quite good for a heavy tank.”
To find out more, check out GoHaRu.Com portal.