I not so SURE but I THINK so!
That they PN plans of producing their own Nuclear submarine might be based on S-20 design but might weigh around 7000 Tons when submerged. And it might have some Ballistic Missile capability as well.
I think if GoP will give PN the money which it needs then the submerged fleet will look like in 15 year:
5-7 SSBNs
20-25 SSKs
12+ Coastal SSKs
So how much does S-20 Displaced?
Who are you going to fight with that many subs ? US Navy ??