Is the Universe isotropic but not Homogenous per General relativity??

Answer 1

That depends on whether you believe in a closed universe or an open one. In Einstein's day, the closed system was the reigning paradigm, so it was isotropic. No one has advanced a theory that the universe is homogenous that I know of, so I would venture that with GR it would be heterogenous, but you could check that with a search engine.

Answer 2

Do you understand what either term means?

According to the Cosmological Principle (NOT general relativity), it is assumed that the universe is isotropic AND homogeneous, based on observations of the cosmic microwave background radiation. This has nothing to do with relativity.