  We investigate the role of higher order couplings, along with the
condensation of antikaons ($K^-$ and $\bar K^0$), on the properties of neutron
star (NS). We employ extended versions of the relativistic mean-field model, in
which kaon-nucleon and nucleon-nucleon interactions are taken on the same
footing. We find that the onset of condensation of $K^-$ and $\bar K^0$ highly
depends not only on the strength of optical potential but also on the new
couplings. The presence of antikaons leads to a softer equation of state and
makes the neutron star core symmetric and lepton-deficient. We show that these
effects strongly influence the mass-radius relation as well as the composition
of neutron star. We also show that the recently observed 1.97$\pm$.04 solar
mass NS can be explained in three ways: (i) a stiffer EoS with both antikaons,
(ii) a relatively soft EoS with $K^-$ and (iii) a softer EoS without antikaons.
