RAK7289V2 Change country plan

Good day,

  1. Does the RAK7289V2 have different hardware versions for EU868 and KR920 ?
  2. Is it possible to set the frequency plan KR920 for the EU868 version (this band is absent in the Worldwide selection menu

    ), or is it possible to set a custom frequency plan with KR920 parameters in the protocol settings ?

EU868 and KR920 are different hardware.
You cannot change a gateway that has hardware for EU868 to KR920.

maybe is it possible to create a custom frequency plan within the EU868 band excluding some channels (at the consumer some channels are overlapped by GSM communication)

No, the concentrator in the gateway cannot work in 800MHz. It is designed for 900MHz.