Good luck for your Nunc Pro Tunc. If it is granted, then you will be back to your status and any "out of status" will be removed from your file ( In my opinion ). However, I am not sure how long it will take to have your case reviewed. Don't know what you meant by 15 days.

" I don't have status, how they are going to change my status to F-1 when I have no status?"

I am confused on this question. Are trying to transfer your h1b to a new employee or are you trying to re-instate your status from h1b to f1. Btw, It is hard to get a f1 status from h1b.
Please be more clear on your case and we might able to help you.

"Any other options to stay here? "
Most probably None. I don't know about your case but in most of the cases that is MTR / Appeal generally you don't have any status. means you can't stay in the US. but if you do that will count towards your illegal presence if your case is refused.

Disclaimer - I am not a lawyer and this is just personal opinion. Please consult an attorney for accurate information.