Individual born in Taiwan between 10 February 1980 and 9 February 2000 whose mother is a Taiwan national with a household registration in Taiwan and father is a foreigner, can get taiwanese citizenship.
If your mother was a Taiwanese citizen when you were born, and she is now reside in Taiwan with household registration, you can get TARC, as @paperclip said.
There is no ARC category for that purpose. You need to get an ARC with other reason, or TARC to join your mother. To get a TARC, you first should get a Taiwanese passport as a national without household registration.
You can contact to Taipei Economic and Cultural Office in your region for further information. You will also find useful threads in the dual nationality section in this forum.