Naveed Akram, 24, faces 59 charges over the December 14 attack, including 15 counts of murder, 40 counts of wounding with intent to murder and a terror offence.
Police allege he carried out the mass shooting with his father Sajid, 50, who was shot dead at the scene.
During a brief status mention at a Sydney court on Monday, Akram appeared via video link from Goulburn Correctional Centre, a maximum-security prison southwest of Sydney, where he is being held on remand, media reported.
Akram wore prison greens and sat mostly in silence during the proceedings. He spoke only to acknowledge that he heard a discussion about extending non-publication orders for the details of the victims.
Outside court, Akram's lawyer Ben Archbold said his client was doing "as well as he can be" given the "very onerous conditions" in prison.
Archbold said it was too early to say how Akram would plead and that he had not discussed details of the alleged attack with him.
"I haven’t spoken to him about the attack in that regard," he told reporters.
"All that we’re doing at the moment is starting the process … we’re waiting for the brief to be served, there’s nothing more I can say."
Archbold added that he had visited Akram in prison.
"He’s just a client, and he’s a client that needs to be represented. And we don’t let our personal view get in the way of our professional obligations. The matter has been adjourned, I have nothing more to say."
The case is expected to return to court in April.
(Reporting by Christine Chen in Sydney; Editing by Michael Perry)
A person stands by floral tributes left at a makeshift memorial at Bondi Beach in Sydney, Australia, 16 December 2025. Australia is in mourning following an attack on the Jewish community's Hanukkah festival celebrations on 14 December that left at least 16 people dead, including one gunman. EPA/MICK TSIKAS AUSTRALIA AND NEW ZEALAND OUT