Head Rings --- I have no Idea.
The only Rings which are in Head are Piston Rings, if they need to replace this means that bike ridden in long, and even the Rings are replaced the bike will need to replace a piston in a short run to 0.5 if the current piston size is "0" (zero)
and 70K for such bike is on the higher end, as compared to a same bike in Karachi.