Understanding the physical state of the interstellar medium of protogalaxy at high
redshift plays a key role in our understanding of galaxy formation. Although it is not
possible to directly observe the highly redshifted galaxies, but their signature as
absorption line in the background quasar spectrum allow us to study them in both
optical and radio regions. The 21-cm line, caused due to the hyperfine splitting in Hydrogen atom,
is the signature of cool gas present in the interstellar medium (ISM) of this highly redshifted galaxy.
In this regard we study the quasar-galaxy pair (QGP) J1443+0214 with z_qso =1.82, z_abs = 0.3714,
by searching for the 21-cm HI absorption at the redshift of foreground galaxy. We use the
GMRT archival spectral data centered around 1041.68 MHz with 4.17 MHz bandwidth and process it
using Astronomical Image Processing System (AIPS) to obtain HI 21-cm absorption line.
We find a very prominent HI absorption at the redshift of foreground galaxy (z_abs = 0.3714),thus concluding
that a cool gas phase of ISM is present in this galaxy, estimate the optical depth and
spin temperature of HI.