Instantiate object with attached variable

If I instantiate an object newTile:
Instantiate(newTile, position, transform.rotation);

Can I add a variable to hold a value and be able to access it like this:

newTile.value = 5

then be able to access it with ‘newTile.value’?

This isn’t working - how would I go about doing something similar?

Is there some tutorial that shows how to instantiate several objects and the access them such as you sould have to do for a board or card game?

You can access variable of instantiated object using GetComponent Method of the game object

GameObject b = Instantiate(newTile, position, transform.rotation);
<<YourScripts>> a = newTile.GetComponent(typeof(<<YourScripts>>)) as <<YourScripts>>;
a.Value = 5;

Or you can use it also like that 
GameObject b = Instantiate(newTile, position, transform.rotation);
b.GetComponent(typeof(<<YourScripts>>)).value = 5;