Wait, KSHMR is a known DJ and producer, part of Los Angeles EDM scene. He started with mixtapes around 2013, and Vol. 1 was the debut. Vol. 4 was released in 2013, then Vol. 8 in 2015. There's no official Vol. 5 or 6. Maybe there's a mix-up with the numbers or the user is referring to a non-official release.