Are mechanical or electromagnetic waves reflected? or are they both reflected? i'm : (

ANY waves are reflected, if they hit the right kind of barrier that can
reflect them.

Sound waves are mechanical waves.  They'll reflect from any wall
or hill.  When that happens, you might hear an echo.

Lake or ocean waves at the shore are mechanical waves.  If there's
something like a wall or a pier sticking out from the shoreline, then
the waves reflect from it, and you can see new waves on the water,
going off sideways.

Light waves are electromagnetic waves.  When light hits, let's say,
a smooth piece of glass with a coating of metal on one side, the light
reflects from it, and we say to each other "Oh !  Look !  A mirror !" 

If the surface of a pond is quiet and smooth, then light can reflect
from it, and you can see your face in the surface of the water.
Sometimes when you're looking across a pond or a small lake,
you might see a copy of the trees, upside down in the water.
When you see that, light from the real trees is going down to
the water, reflecting off of it, and coming to your eyes.

Radio waves are electromagnetic waves.  They can reflect from
high, ionized layers of the atmosphere, and they can even reflect
from buildings.