In fact, I ever asked the Kabul controller myself for 2-3 times but the answer wasn't clear. He sad I can deviate up to 10NM from the route, further than that I will then enter the uncontrolled airspace. Just keep him informed. That's all.
Does this mean I can go beyond 10NM if I really needed to by informing him before? Any provision I need to know in doing so?