I like how this poor guy asks for advice, and here comes the idiot retard mobile starting to complain about balance. WTF ????
Anyways, as for the IS-2, here are a couple of ways you can kill the IS-2.
First, ostheer has much less problems than OKW. Generally how you counter the IS-2 as ostheer is well positioned PaK 40s. If you have a tiger, 2 pak 40s are enough for an IS-2. If you go lightning war, save up for the stuka close air support since it does absolutely devastating damage to the IS-2. If you don't, consider placing some teller mines here and there. Pshrecks are not generally a good idea. They only have 30% chance to pen the IS-2.
If you dont get tiger and istead opt for PIVs, get 3 PaKs. Good PaK positioning is key. Ostheer late game these days is all about PaK positioning. Realistically you dont even need any armor at all (especially with USF) as long as you have excellent PaK positioning. (Check how Captainsprice sometimes plays). Sometimes he gets even 4 PaKs.
Anyways, the key word here is positioning. Losing a PaK is devastating, especially if you have your own armor on the field. A soviet 6 man pak-40 team will spell doom for your armor.
OKW. Now as OKW it is much,much tougher. Now what you want to do is place down schu-mines. If you are on a close quarters map like kholodny ferma where it is not possible to exploit the longer range of the JPIV/Panther. KT on an equal game is not really an option since by the time you get a KT he already has 2 IS-2s, or if he is smart and sees you are going for a KT, he is going to get a double kv-8 and just roast you.
What i haven't seen alot of people do is use the command panther. Its "mark target" ability makes any tank take 50% more damage, which is absolutely *devastating). Of course it costs 200 fuel, but the mark target + the fact that the command panther can spot for itself, thus making it a much better combat and support unit than a regural panther, makes it very worth it.
But, if you are on an urban map, what you need to do is get a lot of raketenwerfers. Lots and lots of raketenwerfers, they are quite cheap and OKW floats MP anyways, so you should get 3 or even more. This doesn't work as well as ostheer pak-40s because the raketenwerfer has shorter range, so it might get wiped if you get unlucky. But once it has vet they get alot better.
PaK-43 is good to keep the IS-2 out, but you wont kill it with it.
Hope this helps you a bit. Keep in mind that i am talking from a 1v1 perspective here. If you are playing other modes someone else will help you out
Also provide a replay if you can