Family members have gathered two days after Mr Mandela's eldest daughter said he was putting up a courageous fight from what she called his "deathbed".
He spent nearly three months in hospital with a lung infection.
Mr Mandela, 95, led South Africa's transition from white-minority rule in the 1990s, after 27 years in prison.
The BBC's Mike Wooldridge, who is outside Mr Mandela's home in the Johannesburg suburb of Houghton, says it appears to have been an unusually large family gathering on this occasion.
Among those attending was family elder Bantu Holomisa,
A number of government vehicles were there during the evening as well, our correspondent says.
