  We examine the consistency of HI properties with the unification scheme for
radio galaxies and quasars, and any correlation with the symmetry parameters
for a sample of CSS and GPS sources. In our sample, 15 out of 23 galaxies
exhibit 21-cm absorption as against 1 out of 9 quasars, which is broadly
consistent with the unification scheme. Also there is a tendency for the
detection rate as well as the column density for galaxies to increase with core
prominence, f_c, a statistical indicator of the orientation of the jet axis to
the line of sight. This can be understood in a scenario where radio sources are
larger than the scale of the circumnuclear HI disk so that the lines of sight
to the lobes at very large inclinations do not intersect the disk. The sources
in our sample also exhibit the known anti-correlation between HI column density
and source size. This suggests that small linear size, along with intermediate
values of core prominence, is a good recipe for detecting 21-cm absorption in
CSS and GPS objects. Some of the absorption could also be arising from clouds
which may have interacted with the radio jet. The HI column density and
velocity shift of the primary absorption component, however, show no dependence
on the degree of misalignment and the separation ratio of the radio sources.
