Melbourne is 7 hours ahead of Istanbul
Best overlap: 8:00 AM to 11:00 AM in Istanbul is 3:00 PM to 6:00 PM in Melbourne.
Aim for 8:00 AM to 11:00 AM Istanbul time — that's 3:00 PM to 6:00 PM over in Melbourne. With 3 hours of overlap, 8:00 AM in Istanbul (3:00 PM in Melbourne) is a comfortable, repeatable slot for both sides. These times hold for most of the year, but Melbourne's daylight saving (which Istanbul doesn't use) shifts them by an hour twice annually.