The RN2483 implements a node which only listens after data has been transmitted, it requires the encryption keys as it decrypts the data. A gateway needs to listen continuesly, forward the data that is received to the back-end and does not decrypt. So LoRaWAN firmware of the module is totally unsuited for gateway usage.
You will probably not need to make changes to the radio commands, however as radio commands only implement the LoRa radio stack and not the WAN part you will need to write that part yourself. Or try to adapt the available single channel gateway code to talk radio commands to a RN2483 over a serial port in stead of a setting lora registers on a RFM/SX module connected with SPI. However as a RFM/SX module is cheap (costs less than an RN2483) I would not bother as I stated in my previous message.