Leh DC office is closed on Sundays and other national holidays. Hence, you should plan your Leh Ladakh trip such that your Leh local sightseeing day does not start with Sunday or a holiday. Having said that, I have heard that DC office is sometimes open on Sunday for half-day as well but I will say don't count on it. If that is the case, best it to apply the Ladakh inner line permits online or get the arranged in advance through some travel agent.