Speaking at the event, he said the only appropriate punishment for his son's killer is the death penalty by hanging.
According to a report by the Times of India, "I want to request the authorities that the only befitting punishment for this act is hanging till death," Santani said.
The condolence event, held near the school, was organised by Jan Akrosh Vali Mandal, a parents' association. During the gathering, Girish Santani also strongly criticised the school's handling of the incident and urged authorities to shut it down.
"My child was injured, and the authorities were aware of it. He lay there for 50 minutes without receiving any help. No one called the police or dialled 108 for an ambulance," he said.
The stabbing incident took place over an issue between the two students on August 19 near the main gate of the Seventh Day Adventist School located in the Khokhra area of Ahmedabad.
In the post-mortem of the deceased, doctors found that while the external stab wound was only 1.5 cm, it had fatally damaged a major abdominal artery and vein. Around 2.5 litres of blood had collected in his stomach.
Surgeons had carried out a three-hour emergency operation, but he succumbed to internal bleeding that caused hypovolemic shock.
In a separate incident in Rudrapur, Uttarakhand, a Class 9 student allegedly shot his physics teacher inside the classroom on Wednesday. According to police, the student was reportedly angry after being slapped by the teacher two days earlier.
The teenager has been taken into custody and will be presented before the Juvenile Justice Board, said Abay Pratap Singh, Additional Superintendent of Police (Kashipur).