Light from the Andromeda Galaxy takes approximately 2.5 million years to reach Earth. In that time many things will have changed in the galaxy, but it is predicted to still exist.
Andromeda is a galaxy, and one of the closest galaxies to our own, the Milky Way.
Andromeda is approximately 2.5 million light-years away, which means a ray of light takes 2.5 million years to travel from Andromeda to us.
Galaxies usually cease to exist when they run out of hydrogen and helium required to form stars, or when they collide with another galaxy.
The Andromeda Galaxy is moving towards the Milky Way, and the two galaxies are predicted to collide in 4 billion years.
So, it's safe to assume that in the 2.5 million years since light rays reaching us left the Andromeda Galaxy, the galaxy has continued to exist.