Radio and Television Act Article 19

Locally produced programs shall not be less than 70 percent of the total radio/television programs; among them, locally produced drama programs that are broadcasted in the main time slot shall not be less than 50 percent of the programs with the same category.Foreign-language programs shall carry Chinese subtitles or broadcast with Mandarin narration. If necessary, the regulatory agency may instruct that the programs be dubbed in ChineseThe identification, category and main time slot of locally produced program as well as other relevant and to-be-followed details shall be regulated by the regulatory agency.
中文原文 廣播電視法第19條
廣播、電視節目中之本國自製節目,不得少於百分之七十;其中於主要時段播出之本國自製戲劇節目不得少於同類型節目之百分之五十。
外國語言節目,應加映中文字幕或加播國語說明,必要時主管機關得指定改配國語發音。
第一項本國自製節目之認定、類別、主要時段之界定及其他相關應遵行事項之辦法,由主管機關定之。

English translation for reference only; the Chinese text prevails. Not legal advice.