Ni1-xZnxFe2O4 (x = 0.0, 0.25, 0.50, 0.75, 1.0) ferrites have been studied using the Mossbauer effect. The aim was to investigate the dependence of magnetic behaviour of octahedral-sublattice on the number of tetrahedral sites, n, occupied by Zn2+ ions. Magnetic, relaxation and paramagnetic regions have been classified from n vs H-oct and n vs Gamma(oct) plots. Ni2+ ions show a tendency for tetrahedral sites.