Could you explain a bit more what do you mean by "an initiative application"?
I would say apply to the vacancy via the RB website unless the application is for a specific function (RB calls them Competence Centers - CCs), then your application would be considered as a generalist.
If you have a preference for a specific industry, then you can make explicit during the interview process and they would let you know if it works or not. (depending on office location, that CC might be requiring extra interns or not) - also during internships, RB likes to rotate their interns across different functions/industries so they can get wider exposure.
I hope this clarifies a bit the situation.
If you have additional questions regarding RB, feel free to drop me a message.