Is metamorphic rock non porous rock?

Yes. Since metamorphic rocks are rocks that have been changed through intense heat and pressure, they have been compacted and are more dense. For example, a conglomerate is a sedimentary rock comprised of large grains of gravel that have been cemented together, and can be porous. When a conglomerate undergoes massive heat and pressure, it is metamorphosed into a metaconglomerate, which is more dense and not at all porous.