  We consider generic toric Tri-Sasakian 7-manifolds X_7 in the context of
M-theory on AdS_4 X X_7 and study their AdS/CFT correspondence to N=3 SCFT in
3D spacetime. We obtain volumes of Tri-Sasakian manifolds and their
supersymmetric 5-cycles via cohomological integration technique, and use this
to calculate conformal dimensions of baryonic operators in the SCFT side. We
also propose quiver-type gauge theories for UV description of the corresponding
N=3 SCFT.
