Per the 10/19 PDC 5.3R3 release notes (https://www.pulsesecure.net/techpubs/pulse-client/pulse-secure-client-desktop/5.3rx):
Table 3: Pulse Secure Desktop Client Qualified Platforms
macOS 10.12, 10.11 and 10.10, 64 bit
Table 4: Pulse Secure Desktop Client Compatible Platforms
macOS 10.13, 10.9, 64 bit