Question

WHAT PLANET IS GAMORA FROM?

Answer 1

Gamora is adopted daughter of of Thanes

Answer 2

Xandar.

A recent viewing for the second time of the first Guardians of the Galaxy film will bring Thanos's seemingly genuine words fully into question, as well as his claim that his killing of Gamora's home planet helped them to rise.

When the Guardians get arrested on Xandar, Gamora's scan finds out that she is indeed the last surviving member out of her own people.

That effectively means that Thanos, even if he killed half of the population yet he succeeded in wiping all of them out.