I think you have your facts wrong. There was really only one incident that reached Western news media and four men were executed for the incident (the fifth killed himself). The police identified and captured suspects almost immediately after the incident and it went to the courts right after. So I’m not sure where the claim that they weren’t prosecuted is coming from. You can view the timeline of the incident at https://edition.cnn.com/2020/03/19/asia/india-rape-execution...