How can I find gameobject by certain position

hello I have a question. please help me!

I have many blocks(square) in Unity2d. And if I clicked one block. I want check it's up,down,left,right block. I want to figure out w$$anonymous$$ch is same block(I want to make 8 kinds of block in t$$anonymous$$s game)

When I click one block. I can get block's name and position by "transform.position" and "t$$anonymous$$s.name" by script w$$anonymous$$ch is included in gameObject.

So I try to check upside block by position. with plusing y in vector3. like "new Vector3(x,y+n,z)"

Is it possible to find gameobject by certain position?

And Please tell me if there is a better way to check 4side of the block!!