  Low-energy supersymmetric models such as MSSM, NMSSM and MSSM with vectorlike
fermion are consistent with perturbative unification. While the non-minimal
extensions naturally explain Higgs mass and dark matter in the low energy
region, it is unclear how seriously they are constrained in the ultraviolet
region. Our study shows that $i)$, In the case of embedding MSSM into
$\rm{SU}(5)$, the fit to SM fermion masses requires a singlet $S$, which leads
to unviable embedding of NMSSM into $\rm{SU}(5)$ because such $S$ feeds singlet
$N$ a mass of order unification scale as well. $ii)$, Similar result holds in
the case of embedding NMSSM into $\rm{SO}(10)$, where $S$ is replaced by some
Higgs fields responsible for $\rm{SO}(10)$ breaking. $iii)$, On the contrary,
for the embedding of MSSM with $16$-dimensional vectorlike fermions into
$\rm{SO}(10)$, the Higgs field responsible for the vectorlike mass of order TeV
scale can evade those problems the singlet $N$ encounters because of an
intermediate mass scale in the $126$-dimensional Higgs field.
