The one that comes first out of two or more possibilities
जो पहले हो
English Usage: The project must be completed by the end of the month or when we receive the funding, whichever is earlier.
Hindi Usage: परियोजना को महीने के अंत तक या जब हमें फंडिंग प्राप्त हो, जो पहले हो, पूरा करना होगा।