  By a systematic survey of the parameter space we confirm our
surmise\cite{gmblm} that the Minimal Supersymmetric GUT(MSGUT) based on the
${\bf{210\oplus 126\oplus {\bar {126}}\oplus 10}}$ Higgs system is incompatible
with the generic Type I and Type II seesaw mechanisms. The incompatibility of
the Type II seesaw mechanism with this MSGUT is due to its generic extreme
sub-dominance with respect to the Type I contribution. The Type I mechanism
although dominant over Type II is itself unable to provide Neutrino masses
larger than $ \sim 10^{-3}$ eV anywhere in the parameter space. Our
Renormalization Group based analysis shows the origin of these difficulties to
lie in a conflict between baryon stability and neutrino oscillation. The MSGUT
completed with a {\bf{120}}-plet Higgs is the natural next to minimal
candidate. We propose a scenario where the {\bf{120}}-plet collaborates with
the {\bf{10}}-plet to fit the charged fermion masses. The freed
{{\bf{126}}}-plet couplings can then give sub-dominant contributions to charged
fermion masses {\textit{and}} enhance the Type I seesaw masses sufficiently to
provide a viable seesaw mechanism. We give formulae required to verify this
scenario.
