[en] The decay of ^{176,182,188,196}Pt* compound systems formed in ⁶⁴Ni+^112,118,124Sn and ¹³²Sn+⁶⁴Ni reactions is studied by using the well established dynamical cluster-decay model (DCM), with effects of quadrupole deformations (β₂) and ''optimum'' orientations for hot (compact) configurations included. Our calculations indicate that the mass fragmentation yields change from predominantly symmetric to predominantly asymmetric with the increase in number of neutrons in Pt* nuclei. The comparison between the experiments and DCM calculations are excellent for evaporation residue cross-sections at both the below and above barrier energies, but the fission data show a significant quasi-fission component at the highest one or two energies.