Different engine manufactures tune their engines to run on different octane levels. Generally the higher compression the higher the octane.
That said have a look in your owner’s manual or ask the dealer, if it's tuned to run on regular you will just be wasting money, if it's tuned to run on premium and you run regular you will probably hear it ping under a load.
If you do any mods that increase the compression you will want to run premium at a minimum, then you need to start looking at race gas….
I would suspect that a 200cc Gio will run fine on regular fuel.