In my campaign I'm being chased by a revenant and I'm about to reach level 7. I was thinking of taking banishment to cast on the revenant. The spell states that it brings creatures native to my plane back after a minute but if the creature belongs to another plane it goes there. So because the revenant is dead would it go back to the land of the dead?
It depends on the lore of the setting you are playing in. Some have planes which count as native to some or all undead, while others do not.
Revenants are usualy creatures that arose as undead to complete some misson important to them. They could still be counted as native to the plane where they belonged in life.
You should ask your GM. If such a thing is common knowledge in the world, you might get a direct answer. Or you might need the counsel of someone trained in Arcana or possibly Religion to get an answer. Since you are a caster, you most likely have proficiency in one of those skills.
No, because the soul is still native to the material plane.
According to the description in the MM (pg. 259), a revenant is a soul that re-entered its original body:
A revenant forms from the soul of a mortal who met a cruel and undeserving fate. It claws its way back into the world to seek revenge against the one who wronged it.
This is essentially the same as being resurrected by the resurrection spell:
You touch a dead creature that has been dead for no more than a century, that didn't die of old age, and that isn't Undead. If its soul is free and willing, the target returns to life with all its hit points.
In both cases, the body is being reanimated by the original soul that animated it. Additionally, when you cast banishment, you're casting it on the whole creature, soul and body, not just the soul.
If you could banish a Revenant, then any creature that has ever died and returned to life could also be banished by the Banishment spell.
Finally, one could argue that a revenant soul possessing a different body could be banished, but a wizard could also replicate such a situation using Magic Jar. Is a material plane wizard inhabiting another body suddenly native to a different plane?