  The different scenarios of spontaneous breaking of D-parity have been studied
in both non-supersymmetric and supersymmetric version of the left-right
symmetric models(LRSM). We explore the possibility of a TeV scale $SU(2)_R$
breaking scale $M_R$ and hence TeV scale right handed neutrinos from both
minimization of the scalar potential as well as the coupling constant
unification point of view. We show that although minimization of the scalar
potential allows the possibility of a TeV scale $M_R$ and tiny neutrino masses
in LRSM with spontaneous D-parity breaking, the gauge coupling unification at a
high scale $\sim 10^{16}$ GeV does not favour a TeV scale symmetry breaking
except in the supersymmetric left-right (SUSYLR) model with Higgs doublet and
bidoublet. The phenomenology of neutrino mass is also discussed.
