Two of the men fled the scene and are yet to be arrested.
In a video that has gone viral, two of the men are seen beating Jacob, who is lying on the ground unable to defend himself.
One of the men is heard saying, "Skiet hom [Shoot him]."
Dudu, who filmed the vicious attack, sounds distressed and approaches the men asking if they would hit her even though she is a woman.
At the end of the video the men are heard calling her a "k*****".
The fast-food chain restaurant has condemned the incident.
KFC corporate communications manager Gail Sham said the company had been in contact with a member of the Sono family and extended its apologies and support.
"The violence in the footage is inexcusable and we condemn any form of violence in our nation," she said.
The family has requested privacy.
Police spokesman Kay Makhubela said only Harding had been released on bail.
"The three other suspects were denied bail after they were found to have pending assault charges and gave false addresses.
"The suspects will appear again in the Pretoria Magistrate's Court on Friday."