I went on the interview with my fiance yesterday, and when the consulate saw me she decided for a split interview...afterwards she gave my fiance letter section 221(g) and will send the petition back to USCIS. I would like to know how do I start the waiver or what can i do before the petition is sent back to the USCIS? I am still at the foreigin country is there anything I can do? What happens now?

i answered on the other thread, your job is to work now quickly to keep it there and not returned

From reading the other thread, this is not a waiver situation. Your fiance does not have an immigration overstay or illegal entry that caused the denial.