He studied literature at Damascus University and in 1919 began to work for the Ministry of Education.
In the same year, be began writing for the newspapers al-Ayyam (Damascus) and al-Hayat (Beirut). Munir opposed the French Mandate for Syria and Lebanon imposed in 1920 and in 1925 left his job to join the revolt of Sultan al-Atrash. At the end of the revolt, in 1927, Rayyes returned to Damascus, where he was a regular writer for al-Hayyat.
With the fading of the League in 1935, Rayyes moved to Palestine from 1936-38 to join Haj Amin al-Husseini in the 1936–39 Arab revolt in Palestine. In 1945, Munir founded a newspaper, Barada, working as its editor-in-chief, and another in support of Husni al-Za'im's 1949 coup, called al-Inkilab (The Coup d'Etat). 1954 also saw a short-lived experiment with running a shareholding company to print Syria's four main papers, al-Qabas, al-Ayyam, Alif Ba', and al-Sham.
Rayyes supported Arab nationalist movements in the 1950s and Gamal Abdel Nasser of Egypt both during and after the United Arab Republic. Rayyes is also noted for his book Al-Kitāb al-Dhahabī li'l-Thawrāt al-Waṭaniyya fī al-Mashriq al-ʿArabī: al-Thawra al-Sūriyya al-Kubrā (The Golden Book of Nationalist Revolutions in the Arab East).
In 1938 he became the director of political affairs at the Damascus police department. Rayyes supported the 1963 Syrian coup d'état but once their power was established, the Baath party closed Barada.