University events that have invited members of the public and/or dignitaries should include a Welcome to Country. Special events can also include a Welcome to Country, determined by the managing staff.
If you are officiating at a ceremony or event, it is respectful to ask the Elder how he/she would prefer to the addressed. Some Elders do not like to be named Aunty or Uncle by non-Aboriginal people.
If you are speaking directly after a Welcome to Country, it is appropriate to make a brief Acknowledgment of Country, for example: "I would also like to pay my respects to the [language groups] people and their Elders past and present."