The retired general was treated in a London hospital and discharged the following day.
Brar spearheaded 'Operation Blue Star' a military raid against Sikh separatists in Golden Temple that killed an estimated 1,000 people in 1984.
Later that year Prime Minister Indira Gandhi was assassinated by her own Sikh bodyguards triggering a further wave of retaliation that left nearly 3 000 Sikhs dead.
Barjinder Singh Sangha, 33, Mandeep Singh Sandhu, 34, and Dilbag Singh, 36, appeared at a preliminary hearing at London's Southwark Crown Court on Friday the Press Association reported.
They are charged with wounding with intent to do grievous bodily harm. Singh Sangha is also charged with the common assault of Brar's wife Meena.
The three defendants were held in custody and will appear in court again on January 18.