  The fission of highly excited compound nuclei formed in heavy ion induced
fusion reactions has emerged as a topic of considerable interest in the recent
years.
  Dissipative dynamical models based on the Langevin equation were developed
and were applied successfully for fission dynamics of highly excited heavy
nuclei. However, Wall Friction(WF), the standard version of nuclear friction
when incorporated in the Langevin dynamical model was not able to reproduce
simultaneously experimental data for both prescission neutron multiplicity and
fission probability. Consequently, an empirical reduction in the strength of
the wall friction was found necessary to reproduce the experimental numbers by
many workers. Interestingly, a modification of the wall friction was proposed
recently where the reduction was achieved microscopically. This modified
version is known as the chaos weighted wall friction(CWWF) which takes into
account non-integrability of single particle motion. The work in my thesis aims
at using this strongly shape dependent version of friction (CWWF) in the
Langevin dynamical model coupled with particle and gamma evaporation in order
to verify to what extent it can account for the experimental data of fission of
hot nuclei. The experimental data includes excitation functions of prescission
neutron multiplicity, fission probability as well as evaporation residue
cross-section of a number of nuclei. The importance of transients in nuclear
fission is also discussed. The present endeavour is an effort to obtain a clear
physical picture of nuclear dissipation which in turn will help in solving many
open problems related to collective motion, and in particular, nuclear fission.
