The African Union lists the Kingdom of Morocco under Northern Africa with the dates 1963 and 31 January 2017
Background
The African Union's own member state profiles list the Kingdom of Morocco, abbreviated as Morocco, in the Northern Africa group. The column for the date of joining the OAU or AU shows 1963 and 31 January 2017. The first date is its membership of the Organisation of African Unity, the Union's predecessor. The second is the date it rejoined the continental body after an absence of more than three decades. Morocco is not a member of ECOWAS, which is the West African regional bloc. Questions in both Kerala PSC and UPSC pair a country with the continental and regional bodies it belongs to.
In plain words
OAU Organisation of African Unity — The continental body founded in 1963 that the African Union replaced.
ECOWAS Economic Community of West African States — The West African regional bloc; Morocco is not a member of it.