can my cousin get free repair for his console?

My cousin bought his xbox 360 used and it has rrod now. Will he still be able to repair it if he puts the codes and stuff in?

if he JUST got it he can return it, and if not then he would have to call microsoft and check the serial number to see if the warranty is still good

Call M$ and they will ask for your serial and product number, they can tell you. If the console is less than 3 years old, it is covered by M$. Once they replace the console, theirs I believe a 90 day warranty on it.