Your Gameobject should have any type of collider component then in script do the following:
//Use UIEventListener to bind your gameobject with your desired method
public GameObject YOUR_BUTTON_GAMEOBJECT;
UIEventListener.Get(YOUR_BUTTON_GAMEOBJECT).onClick += YOUR_METHOD_NAME;
//METHOD SIGNATURES
void YOUR_METHOD_NAME(GameObject gameObject){
//On Click Stuff
}
Hope this helps