The Renault radio code is a security feature designed to prevent theft of your car's audio system. If the radio is disconnected or the battery is replaced, the radio will lock and require a code to function. This code is unique to each vehicle and radio system.
While formal academic papers are rare, you can find the actual logic in open-source repositories like the renault-radio-code-list on GitHub or the m-a-x-s-e-e-l-i-g generator renault radio code free