Ray Wi-Fi Access Point has RRM and DCS which automatically chooses the best channels available post scanning the environment in a periodic and continuous manner. 

However, it is possible to change the channel manually as well. 

Please follow the below steps.

Step 1:

Go to Profiles -> Available Profiles -> Radio

Press Create Profile

Step 2.

Put a Profile Name

Select the correct Hardware type and the Radio Profile for your Wi-Fi Access Point

Select the Operating Region i.e. the Country.

Select Manual in the Channel Mode

Enter the desired Channel for 2.4 GHz

Enter the desired Channel for 5 GHz

Step 3. 

Put the required comments regarding the change.

and press "Save and Publish"

Thank You