Grid System Like the attache case from resident evil 4

How do I…

Lock items into the grid, be able to rotate them to allow the player more case customization.

What is the expected result

It should lock into grid.
The best way I can describe it, is like the attache case from re4 and re4 remake. Rotating items is also a necessary feature. I’m lost on how to do this, please help.

I know about inventory, and adding and removing items. This is purely visual, with a small bit of coding not allowing you to add more items if all your case boxes are full.