We have succeeded in controlling magnetic properties such as the saturation magnetization, the Weiss temperature and the coercive field using compounds in the series ((NixMn1-xII)-Mn-II)(1.5)[Cr-III(CN)(6)], by the strategy of choosing both ferromagnetic (J > 0) and antiferromagnetic (J < 0) exchange interactions by using the appropriate molar ratios of the transition metal ions. For a composition x = 0.38, the magnetization vs temperature curve exhibited negative magnetization. This type of magnetic behavior can be modeled using molecular field theory with three sublattice (Ni, Mn, Cr) sites.