  We search for dark matter annihilation from galaxy clusters in the energy
range from 1-300 GeV using nearly 16 years of Fermi-LAT data. For this purpose,
we use 350 galaxy clusters selected from the 2500 $\rm{deg^2}$ SPT-SZ survey.
We model the dark matter distribution using the NFW profile for the main halo
along with the Einasto profile for the substructure. The largest signal is seen
for the cluster SPT-CL J2021-5257 with a significance of around $3\sigma$. The
best-fit dark matter mass and annihilation cross-section for this cluster are
equal to $(64.0 \pm 11.8)$ GeV and $\langle \sigma v \rangle= (6.0 \pm 0.6)
\times 10^{-25} \rm{cm^3 s^{-1}}$ for the $\bar{b} b$ annihilation channel.
However, this central estimate is in conflict with the limits on annihilation
cross-section from dwarf spheroidal galaxies and hence cannot be attributed to
dark matter annihilation. Three other clusters show significance between
$2-2.5\sigma$, whereas all the remaining clusters show null results. The most
stringent 95\% c.l. upper limit, which we obtain among the clusters with
significance $>2\sigma$ is from SPT-CL J2300-5331, given by $\langle \sigma v
\rangle = 9 \times 10^{-26} \text{cm}^3 \text{s}^{-1}$ for a dark matter mass
of 10 GeV corresponding to the $b\bar{b}$ annihilation channel.
