Neither, Jupiter is a planet.
An asteroid
The planet Jupiter is outside the asteroid belt, which is located in between the orbits of Mars and Jupiter.
The asteroid belt is not in Jupiter.
Asteorite is not a word found in the English language. The closest I can come is asteroid which is a rock or boulder orbiting the sun along with millions of others between the orbits of Mars and Jupiter.
Main asteroid beltThe asteroid belt
Meteorite.
Jupiter is outside the asteroid belt.
That is called a meteorite. It is basically the same thing as an asteroid, but anything smaller than about 10 meters is called a meteorite.
The asteroid belt is in between Mars and Jupiter.
The asteroid belt is between Mars and Jupiter.
Jupiter orbits the sun outside the asteroid belt.
It could perhaps be called an asteroid.