Hello
I am placing custom mesh on a surface, there would be many meshes placed to the right, left and center of the surface
I have to some how identify if the meshes are adjacent to each other i.e. there are aligned at single point in surface.
X would vary as per mesh size, Y would always be same.
what can we use here?
I am not an expert on this, but I believe adding colliders could help with this. However, best would be to wait for an answer from some of the ‘big brains’ 
in this forum. Shouldn’t be all too long…
You could do a simple intersection test using the bounding boxes like below, testing just the x component (line 383). 
Thank you @Blake