i want to destroy a game object to destory when hit from below but if jump on that object than do nothing.
You should look into the normal vector of a collision. The normal vector is basically the direction the object experiences force from. When hitting an object from below, naturally the force on your character is from above, which means the y-coordinate of the normal vector the player is experiencing is negative. Likewise, when you hit an object from above, the force experienced by your character is from below, which means the y-coordinate of the normal vector is positive.