  We show the occurence of Dirac, Triple point, Weyl semimetal and topological
insulating phase in a single ternary compound using specific symmetry
preserving perturbations. Based on {\it first principle} calculations,
\textbf{\textit{k.p}} model and symmetry analysis, we show that alloying
induced precise symmetry breaking in SrAgAs (space group P6$_3/mmc$) leads to
tune various low energy excitonic phases transforming from Dirac to topological
insulating via intermediate triple point and Weyl semimetal phase. We also
consider the effect of external magnetic field, causing time reversal symmetry
(TRS) breaking, and analyze the effect of TRS towards the realization of Weyl
state. Importantly, in this material, the Fermi level lies extremely close to
the nodal point with no extra Fermi pockets which further, make this compound
as an ideal platform for topological study. The multi fold band degeneracies in
these topological phases are analyzed based on point group representation
theory. Topological insulating phase is further confirmed by calculating Z2
index. Furthermore, the topologically protected surface states and Fermi arcs
are investigated in some detail.
