Repertoire is a mass noun for the variety of skills a person or company is capable of accomplishing. Usually it is used in reference to musicians or theater companies and what parts or pieces they are prepared to perform. However, this term is common enough it can be used outside of the artistic world. Repertoire is pronounced \ˈre-pə(r)-ˌtwär\ (reh per twar).
Repertory is a synonym for repertoire, but it can also has several other definitions. It may mean a certain kind of group of actors performing certain pieces throughout a season. It is also a synonym for repository or a location for objects to be stored. It is pronounced \ˈre-pə(r)-ˌtȯr-ē\ (reh per tor ee).
The plural for repertory is repertories.