Where in NSW Australia is telephone area code 02 84?

Australian telephone area code 02 (or +61 2 in international format) is approximately the state of New South Wales plus the A.C.T., although some towns near a state border are in the area code of the adjacent state. All numbers beginning with 02 8 are in Sydney.

(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, Japan uses 010, Australia uses 0011, and many other countries use different prefixes.)