Mr Syamsuddin was due to give a media conference in Jakarta around 5.30pm (AEDT) but has yet to deliver his decision on the parole application of Schapelle Corby and hundreds of others.
Meanwhile, the head of Kerobokan jail says it's "impossible" that Schapelle Corby will be released on Friday if she is granted parole.
Farid Junaedi told reporters at the Bali prison he was still waiting for word from Justice Minister Amir Syamsuddin on whether the Australian would get parole, after nine years behind bars for smuggling drugs.
TIMELINE: Schapelle Corby case
A prison guard has told AAP that Corby was upbeat on Friday, and joking about staying with the guard when she got parole.
Corby apparently joked that a helicopter was coming to pick her up, and that she would wear a black veil.
Earlier, her sister Mercedes was swamped by the large media pack waiting outside the prison.
Leaving after a visit with her husband Wayan Widyartha, Mercedes was at first reluctant to speak to reporters, but eventually gave in when it became clear it was the only way she could get through the jostling crowd to her motorbike.
"Can you please give us some privacy," she pleaded.
"We don't know yet."
Wayan, speaking in Indonesian, told reporters the family was reluctant to speak ahead of the decision.
"We don't know when she will be released. We keep on praying and, like all of you, hoping for the best," he said.
Mr Syamsuddin was on Thursday petitioned by Indonesian MPs not to be lenient in the case of Corby, who was convicted with smuggling 4.2 kilograms of cannabis into Bali.
Friend says Corby is ready for freedom
Authorities from the departments of immigration and corrections are due to join him at the media conference.
Other visitors to the jail on Friday included Australian consulate staff and the postman, who was also mobbed by the media.
If paroled, Corby will live with Mercedes and Wayan in Kuta.
The former Gold Coast beauty student has always maintained her innocence.
