Del, I feel your post lacks definition.
There are two things that make a suit Italian, one is the fabric, two is the manufacture.
In terms on manufacture an EU standard is that all clothing must contain a label confirming country of manufacture. In a suit you will normally find this in the inside left or right breast pocket.
Fabric wise, look for a fabric name like Zegna or Loro Piana and you will be fine. You should also be able to find a label in the garment about the fabric.
Use these checks and you will avoid buying the sheap imitations, but you should also be guided by price.