if a (NWOHR)Taiwanese marrying to a taiwanese with ID.but the (NWOHR)taiwan came from a country without same sex marriage they can still proceed there wedding plan in taiwan?
I think so. It seems you need authenticated affidavits from two of your relatives.
7.經本部入出國及移民署核准在臺居留之無戶籍國民或無國籍人，無法提出婚姻狀況證明文件者，應查驗其最近親屬二人證明其為單身之書面證明文件。文件係在國外作成者，應由駐外館處驗證。
http://www.laws.taipei.gov.tw/lawsystem/wfLaw_Information.aspx?LawID=A040040041006500-20141119