  The second order Israel-Stewart-M$\ddot{u}$ller relativistic hydrodynamics
has been applied to study the effects of causality on the acoustic oscillation
in relativistic fluid. Causal dispersion relations have been derived with
non-vanishing shear viscosity, bulk viscosity and thermal conductivity at
non-zero temperature and chemical potential. These relations have been used to
investigate the fluidity of Quark Gluon Plasma (QGP) at finite temperature
($T$). Results of the first order dissipative hydrodynamics have been obtained
as limiting case of the second order theory. The effects of the causality on
the fluidity near the transition point and on viscous horizon are found to be
significant. We observe that the inclusion of causality reduces the fluidity of
QGP. It has also been shown that the inclusion of large magnetic field in the
causal hydrodynamics alters the fluidity of QGP
