I have done this before in a quick and dirty way - using colliders. Put a collider and a script with an OnMouseDown method on the prefab, the method will trigger when the tile is clicked.

I would post this as a comment but I don't have the rep to comment. :(

I have done this before in a quick and dirty way - using colliders. Put a collider and a script with an OnMouseDown method on the prefab, the method will trigger when the tile is clicked