There is a thread on the forum, concerning that issue. You have to manually check if the click is within the boundries of your object. I do this in a small game I’m developing now, and it works ok. 
Edit:
This post -> Click on game object
Edit2:
If I understand you correctly, you want to check if you clicked a GameObject, and do something to it? Take my advise with a small grain of salt, since I’m new to this, but I would either let each GameObject check if they where clicked, or put a check in a central script. Let that check loop through the relevant GameObjectsIDs, and check their positions. There are probably lots of ways to do this more efficient, but just try something, to see if it work, then optimize later. 