Most Roland serial numbers have a 7 digit designation containing 1-2 letters and 5-6 numbers. The serial number can be found on a white sticker on the bottom or back panel of the product. With certain battery powered products, this sticker can be found in the battery compartment.
They can also be located on the UPC sticker on the outside of the product box.
The following photos are examples you can use to locate the serial number on your product: