Time frame for deportation on false passport in Australia?

My husband has recieved notice of intention to cancel his permanent visa in Australia 14 days back based on his false passport verification from his homeland country. he is given time to give written response within 14 days whether to agree he complied or non-complied with the conditions on the visa. What do you think how days more he has got before he is out into detention or for voluntarily departure or to fight legally. Can he appeal for assylum staying free in australia without going into detention