  We study the impact of additional couplings in the relativistic mean field
(RMF) models, in conjunction with antikaon condensation, on various neutron
star properties. We analyze different properties such as in-medium antikaon and
nucleon effective masses, antikaon energies, chemical potentials and the
mass-radius relations of neutron star (NS). We calculate the NS properties with
the RMF (NL3), E-RMF (G1, G2) and FSU2.1 models, which are quite successful in
explaining several finite nuclear properties. Our results show that the onset
of kaon condensation in NS strongly depends on the parameters of the
Lagrangian, especially the additional couplings which play a significant role
at higher densities where antikaons dominate the behavior of equation of state.
