  The $(\beta ^{-}\beta ^{-})_{0\nu}$ decay of $^{94,96}$Zr, $^{98,100}$Mo,
$^{104}$Ru, $^{110}$Pd, $^{128,130}$Te and $^{150}$Nd isotopes for the
$0^{+}\to 0^{+}$ transition is studied in the Projected Hartree-Fock-Bogoliubov
framework. In our earlier work, the reliability of HFB intrinsic wave functions
participating in the $\beta ^{-}\beta ^{-}$ decay of the above mentioned nuclei
has been established by obtaining an overall agreement between the
theoretically calculated spectroscopic properties, namely yrast spectra,
reduced $B(E2$:$0^{+}\to 2^{+})$ transition probabilities, quadrupole moments
$Q(2^{+})$, gyromagnetic factors $g(2^{+})$ as well as half-lives
$T_{1/2}^{2\nu}$ for the $0^{+}\to 0^{+}$ transition and the available
experimental data. In the present work, we study the $(\beta ^{-}\beta
^{-})_{0\nu}$ decay for the $0^{+}\to 0^{+}$ transition in the mass mechanism
and extract limits on effective mass of light as well as heavy neutrinos from
the observed half-lives $T_{1/2}^{0\nu}(0^{+}\to 0^{+})$ using nuclear
transition matrix elements calculated with the same set of wave functions.
Further, the effect of deformation on the nuclear transition matrix elements
required to study the $(\beta ^{-}\beta ^{-})_{0\nu}$ decay in the mass
mechanism is investigated. It is noticed that the deformation effect on nuclear
transition matrix elements is of approximately same magnitude in $(\beta
^{-}\beta ^{-})_{2\nu}$ and $(\beta ^{-}\beta ^{-})_{0\nu}$ decay.
