Sorry, I don't have any helpful information.

But I am curious to know how long you (you, not your parents) have been in the US. After having lived here for a while I ,personally, would never ever encourage my parents to try to stay here by filing for asylum. It's just not worth it. Why make them go through all the pain and suffering? I am sure you have your reasons. If you don't mind, could you please explain why you think it is a good idea for your parents to try to get asylum and go through all the physical and mental anguish at an old age?

If you don't wanna answer, please ignore my posts. Hopefully, other people will have good suggestions for you. Good luck!!

I second your opinion sab_Nepaliko_sathi. Why torture your parents in their older age to go through cultural differences and headaches. they will not enjoy it.. please don't do it.. 

not worth it man. dont do it. timro budho ama bau le gas station ma ghanta hanera basne? ani dont forget. you can never fly back home directly. Further ,your status might be terminated anytime.