Reiterating his stand on elections, the separatist leader, 83, said: "Casting votes is against our freedom struggle. We should desist from it."
He alleged New Delhi was hatching "conspiracies" to divide Jammu and Ladakh from the Kashmir valley.
"We won't allow the division of Jammu and Kashmir. It is one – from Jammu to Kashmir to Ladakh to Azad Kashmir."
All roads to Geelani's Srinagar residence were sealed on Sunday morning.
"When all our efforts to persuade the police failed, we decided to organise the conference at Jamia Masjid," said Hurriyat spokesperson Ayaz Akbar.
Geelani gave the police, who were guarding the lane in which his house is located, a slip and directed his car driver to proceed towards the nearby mosque. Participants were asked to wait inside the mosque.
Geelani's address was the first this year. The authorities have repeatedly placed him under house arrest since the execution of Parliament attack convict Afzal Guru in February this year.