  We consider a version of Left-Right Symmetric Model in which the scalar
sector consists of a Higgs bidoublet ($\Phi$) with $B-L=0$, Higgs doublets
($H_{L,R}$) with $B-L=1$ and a charged scalar ($\delta^+$) with $B-L=2$ leading
to radiatively generated Majorana masses for neutrinos and thereby, leads to
new physics contributions to neutrinoless double beta decay ($0\nu \beta
\beta$). We show that such a novel framework can be embedded in a non-SUSY
$SO(10)$ GUT leading to successful gauge coupling unification at around
$10^{16}$ GeV with the scale of left-right symmetry breaking around $10^{10}$
GeV. The model can also be extended to have left-right symmetry breaking at TeV
scale, enabling detection of $W_R, Z_R$ bosons in LHC and future collider
searches. In the context of neutrinoless double beta decay, this model can
saturate the present bound from GERDA and KamLAND-Zen experiments. Also, we
briefly explain how keV-MeV range RH neutrino arising from our model can
saturate various astrophysical and cosmological constraints and can be
considered as warm Dark Matter (DM) candidate to address various cosmological
issues. We also discuss on left-right theories with Higgs doublets without
having scalar bidoublet leading to fermion masses and mixings by inclusion of
vector like fermions.
