A NA Community Coordinator, GhostPrime has written his version of the IS-6 armor changes coming soon in the 9.14 patch, which by the way, according to RU sources it*should be coming in the next few days.
Here it is:
“The IS-6 will be getting the HD treatment along with armor changes in the upcoming 9.14 Patch.
We would like to share with you the changes being made to this tank in the next patch.

First, lets examine the front of the tank:

Pre 9.14 patch:

Post 9.14 patch:

Pros and cons regarding dimensions:
(+ improved; = has not changed; +/- partially improved, partially worsened, with the overall balance as the result; – worsened):
+ Cupola has been decreased in size
+ Turret roof has been decreased in size
= The Lower glacis is decreased in size, but is also slighter weaker
= The height of the vehicle is slightly shorter
+ The driver’s hatch is now increased in size (this is a good thing, as you will notice in the next section)
+ The gap between the track and the fender has been decreased slightly
= Tracks have become noticeably bigger and now comprise external elements of the suspension. This will also make the tank easier to “track”.

Armor Protection
The values displayed in the next images DO NOT factor in normalization. It should be understood that these values are given for comparison purpose only (previous/new model). They should not be used as a basis for conclusions on whether a particular gun would penetrate a certain area of the vehicle’s armor.

Front Armor Pre 9.14 patch:

Tront Armor Post 9.14 patch:

Pros and cons regarding armor protection:
+ Armor thickness of the top section of the upper glacis plate has been increased
+ Armor thickness of the driver’s hatch has increased significantly.
+ Armor thickness of frontal curving sections of the turret has slightly increased.
+ Thickness of the armor strip at the top section of the upper glacis plate has increased.
+ Armor thickness of the lower glacis plate has increased a bit.
+ The part of the fender, which was visible in the frontal view (marked with arrows)*could be penetrated following the rules of two and three calibers, was removed.
= Armor protection of the cupolas has not changed in a noticeably fashion
= Turret inclination has improved, but it will have no effect due to the rules of two and three calibers.
= The armor strip between the lower glacis plate and the upper glacis plate has become wider, but armor thickness of the stripe has decreased.
Armor protection of the lower section of the lower glacis plate has been decreased, due to its decreased effective armor thickness

Armor of the Gun Mantlet:
It can be seen that the size of the embrasure behind the gun mantlet has decreased more than twofold! Therefore, the area where the gun mantlet overlaps the turret armor has been increased significantly, with the resulting armor thickness of 300mm or more in these sections.

Armor of the mantlet Pre 9.14 Patch:

Armor of the mantlet Post*9.14 Patch:

Turret Damage Model:
Turret armor protection is displayed in the image, with areas of effective armor less than 220 mm highlighted—these areas can be viewed as vulnerable spots compared to the rest of the turret’s armor.
The armor protection pattern is displayed this way due to the complex structure of the surface. This variant will be easier to perceive, since we are only interested in weak spots.
It can be seen that the pre 9.14*model had one large weak spot on the left-side of the gun.*The new model has two such areas—at the left and at the right of the gun, but each of them is slightly smaller than the weak spot in the previous model.*Moreover, the new model does not have the weak spot on the gunner’s sight.

Turret damage Model*Pre*9.14 Patch:

Turret damage Model*Post*9.14 Patch:

Side Armor Changes:
Lastly, we examine the changes made to the side of the tank int he new patch, and give the Pros, and Cons of said changes

Side Armor Pre 9.14 Patch:

Side Armor Post 9.14 Patch:

Pros and cons regarding Side Armor:
+ Main side armor plate has has been increased to 142 mm instead of 138 mm.
+ A stripe of reinforced armor has been added (screen of 56 mm + side armor of 136 mm).
+ The prominent part of the fender, which could be penetrated following the rules of overmatching, was removed.
Effective armor thickness of the side frontal plate has decreased a bit, which is balanced by the fact that the effective armor thickness of this frontal armor has increased slightly.”