@ElvisB
Please read the link below you will find an answer to your question.
However in layman's term
In order to get the Full CGT exepmtion, first of all you have to have purchased a house as a PPOR & not an investment & move in to the house for the 6 months in a First year, then you can rent it for 6 years & have to move back in for another 6 months & trigger the 6 year exemption again, you can do this as long as during this period you are not claiming CGT exemption on any other property as a Principle Place Of Residence. (As per ATO you can only have one PPOR at a time) If you buy a property as an investment from the get go CGT will apply, but when you move into it as a PPOR a year later, from that date onwards you can claim exemption, but will be liable for CGT fro the period it was rented as an investment.
So the bottom line is in order to get the Full exemption with 6 year rule, you will need to buy it as an owner occupied property & do not claim CGT exemption on any other property as PPOR.
Treating a dwelling as your main residence after you move out | Australian Taxation Office (ato.gov.au)