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Special linear group of finite ring is finite

Hello there

I am trying to do some computations with the special linear group of a finite ring (given as the quotient ring of a larger ring), and am running into an issue in which it seems that Sagemath doesn't know that the special linear group of a finite ring is finite? Here is a minimal working example which reproduces the error:

Z6 = QuotientRing(ZZ,6*ZZ)
S = SL(2,Z6)
S.is_finite()

In addition, although this link says that I can find all (conjugacy classes of) subgroups of a group G using G.conjugacy_classes_subgroups(), this method does not seem to be implemented for the special linear group above. Why is this so, and which code can I use instead?

Special linear group of finite ring is finite

Hello there

Z6 = QuotientRing(ZZ,6*ZZ)
S = SL(2,Z6)
S.is_finite()

Edit: there have been some helpful comments which show that (for some reason) Zmod(6) is recognised as a finite ring, and can be used instead of QuotientRing(ZZ,6*ZZ)! Unfortunately my actual problem is more like the following:

q = 7
FqT.<T> = GF(q)[]
N = T^2+1
FqTN = QuotientRing(FqT, N*FqT)
S = SL(2,FqTN)
S.is_finite()

Unfortunately, in this case I couldn't find an analogous method to Zmod(6) to construct the finite quotient ring FqTN. Any ideas for what I can do in this case?