Diploma for R

Hello!i have a char 85 lvl in cronos server.when i go 85 lvl i stop playing and i juste start now again becouse a lot of friends of mine start too play.after 8-9months i open the game an i see that i didnt have the diploma that now the game gives too take the r grade items.what i can do to take the r,where i can find or what i can do to take the diploma?thnx