fac (facial, all cis, on one face) and mer (meridional, two cis, one trans, A3 around a meridian) is reserved for octahedral cmplxs of the type MA3B3 and
there is only one isomer of each (make a model). Your cmplx should .: be [Cu(H2O))3(NH3)3]^2+; go from there (neglect J-T distortion).
MA5B: one isomer; MA4B2 cis and trans, Ma3B3 fac and mer; MA3B2C: fac, mer-cis, mer trans; A and B
monodentate ligands; M(L-L)3 and cis-M(L-L)2X2: Δ(R); Λ(L) should get you through your first course in TM coordination chem.