After repeated racist chants directed at him during the match, Milan and Ghana midfielder Kevin-Prince Boateng kicked the ball in anger at a section of the crowd, took off his shirt and walked off the pitch with the rest of the Rossoneri.
Milan players Urby Emanuelson, Sulley Muntari and M'Baye Niang were also targeted by the chants.
Prosecutors had requested four- to six-month sentences.
The ANSA news agency reports that one fan received a 40-day sentence after collaborating with authorities, while the other five fans received two-month sentences.
The fans were also fined a total of €10,000 ($13,000), plus trial expenses.