I'm also interested in Roland Berger's gap year program, so let me share with you what I know. The program takes 9 months and you will get to work in (1) RB in Germany, (2) a startup company, (3) RB abroad. You get a mentor, regular trainings and there will be events where you meet mentors and other participants of the program.
Requirements are the usual for consulting: very good grades (prefferred in economics, engineering, natural sciences), work experience like internships, analytical skills and fluent English.
You should apply online about 3-4months before your starting date. The next one is October 10th, so you would have to apply in June or July. Still plenty of time. If you get invited to the interview, you will expect the normal assessment day at RB, so personal fit questions, case studies etc.
I will definitely apply because I like how the program is built up. It seems innovative and I do like what I have heard so far from RB.
If you have any other questions or maybe want to prepare for the interview together once it's time, let me know.