RFID is a device . . . BTC is a digital currency . . .
As you yourself have pointed out, BTC is not a device it's a digital currency. When people steal your bitcoin, they are not stealing a device. Therefore, there is no RFID (which is a device) to track.
As someone else has already pointed out in this thread, if you tag a hardware wallet with RFID and someone physically takes that hardware wallet from you, then you might be able to track the movement of that hardware wallet device.
If they "hack" your keys and then take your bitcoin (while leaving you the hardware wallet itself), then you will only find the hardware wallet that you still have. You won't find the bitcoins.
If they physically take your hardware wallet and then use that wallet to send your bitcoins to a new address in a different wallet, discarding the hardware wallet in the trash, you might be able to track the hardware wallet and find the trash can it's sitting in, but you won't regain or be able to follow the bitcoins that are now in a completely different wallet.
