How to get GameObject in touch position

Hi everyone.
So, I'm making a 2D mobile game. In order to move your player character you need to touch on a specific game object, let's call them "squares". I'm making a few squares with a tag (i.e "target").
What I need is a way to "capture" the game object in the touch position (
touchPosition = Camera.main.ScreenToWorldPoint (touch.position); ) and check if tag equals to target.

How can I achieve this?

Thanks and sorry for my english!

 

Code (CSharp):

1. OnCollisionEnter2D(Collision2D col)
2. {
3. if(col.gameObject.tag == "Your Tag Here")
4. }

or you could

Code (CSharp):

1. private void Update()
2. {
3. if(touchPosition == gameObject.CompareTag("Your Tag Here"))
4. }

I think that might work.