The Australian Parliament consists of the Queen (represented by the Governor-General), the Senate and the House of Representatives. The Queen is rarely present at a parliamentary session, as it is the Governor-General who represents the monarch at the opening of a Parliament.
A session of Parliament commences on the first sitting day following a general election or prorogation (the formal ending of a session) and concludes either by prorogation, dissolution or at the end of three years from the first meeting of the House.
The current session of Parliament commenced on 30 August 2016.
If you are asking when the Queen was physically present at the opening of a session of Parliament, this last occurred on 8 March 1977. Her Majesty Queen Elizabeth II has attended the commencement of a new session on two other occasions – 1954 and 1974.