If your parents have household registration, check it. If you are registered to their HHR at birth by your parents, you have a citizenship, unless they renounced their and your nationality later. BTW, nationality and citizenship are different. You do not get a citizenship automatically. To get it, you should be registered to the HHR by your parents.
If your parents don’t have HHR, you do not have a citizenship.
Nationality Act
Article 12
For a person who applies to lose his/her nationality according to the preceding Paragraph, under any of the following conditions, the MOI shall not permit the loss of nationality:
- A male from January 1 of the next year after he was 15 years old, who is not exempted from military service and has not fulfilled his military service. But nationals, who reside overseas and were born overseas, and have no household registration in the ROC or moved overseas before December 31 of the year they were 15 years old, shall be excluded.