Mandela, who died in his Houghton home last Thursday, aged 95, will lie in state from Wednesday to Friday.
The GCIS on Tuesday said the procession would leave 1 Military Hospital at 07:00 on each of the days and pass Thaba Tshwane, before arriving at the Union Buildings at 08:00.
The GCIS said the City of Tshwane had activated park-and-ride facilities for the public at the Tshwane Events Centre, LC De Villiers Sports Facility in Hatfield and Fountains Valley Park to the Union Buildings.
The route is: Kgosi Mampuru Street from Jeff Masemola Street to Madiba Street.
Madiba Street from Kgosi Mampuru Street until the Union Buildings.
"Government invites mourners to line this route and form a public guard of honour for Tata Madiba when the remains are transported," Minister in the Presidentcy Collins Chabane said.
"Mourners are advised that cameras, including cellphones, will not be allowed at the Union Buildings," Chabane said.
"We call on members of the public to co-operate with the authorities to ensure that this event is dignified and secure."
Chabane said it was not certain whether Mandela's casket would be open or closed.
On Saturday, Mandela's remains would be transported to the Eastern Cape from the Waterkloof Air Force Base in Pretoria.
On the same day, a procession would take place from Mthatha to Qunu, where the Thembu community will conduct a traditional ceremony.
The state funeral will take place in Qunu on Sunday.
"It [the funeral] is basically run by the national defence force, but at the same time we have to take into account the issues we have to deal with, like our culture, the history of our country and the person we are dealing with," he said.
"Therefore, it might not comply exactly... to what is supposed to happen [in a state funeral]."
Chabane had earlier said foreign heads of state and dignitaries will not be stopped from attending the funeral, but are advised not to.
"Nobody will be prevented from attending..., however, given the size and the scale of the operation and the size of the delegation and the limited infrastructure in the area, we advise [against it]," he told reporters in Johannesburg.
The venue in Qunu could take only 5 000 people, he said.