what will happen when we throw stone from top of earth
There's no such place as the 'top of the Earth', we can however image throwing a stone from a certain height (say 10 km).
The stone,, as it falls towards the Earth' surface, will experience two major forces - like air resistance and gravity. These forces will affect the motion of the stone, its trajectory, as well as the time taken by it to reach the ground. It is such that the force of gravity will acts downwards (towards the ground) and the air resistance will act opposite to its direction of motion; or upwards (towards the sky). These affects will vary with the mass of the stone.
After a while though, the stone will reach the ground with a tremendous velocity (called terminal velocity), it might break upon impact.