Where is telephone number starting with 006?

00 isn't part of the telephone number, it is a commonly used prefix for international calling. That leaves telephone country code +6, which is an incomplete code in the Australia/Pacific region; you need one or two more digits to have a complete country code. For example, +63 is the Philippines and +679 is Fiji.

(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.)