  The discovery potential of light pseudo scalar Higgs boson for the mass range
10-60 GeV is explored. In the context of the next-to-minimal supersymmetric
standard(NMSSM) model, the branching fraction of light pseudo scalar Higgs
boson decaying to a pair of photon can be quite large. A pair of light pseudo
scalar Higgs boson produced indirectly through the standard model Higgs boson
decay yields multiple photons in the final state and the corresponding
production rate is restricted by ATLAS data. Discussing the impact of this
constraint in the NMSSM, the detection prospects of light pseudoscalar Higgs
boson in the channel consisting of at least three photons, a lepton and missing
transverse energy are reported. It is observed that the possibilities of
finding the pseudoscalar Higgs boson for the above mass range are promising for
an integrated luminosity $\mathcal{L}=100 \text{fb}^{-1}$ with moderate
significances, which can reach to more than 5$\sigma$ for higher luminosity
options.
