The Punjab Assembly on Thursday passed a resolution against the Centre's Agnipath defence recruitment scheme.
Gandhi was abroad when the killing took place and returned over the weekend.
Modi brought up the emotive issue of the gurdwara in Kartarpur Sahib, a place sacred to Sikhs as Guru Nanak Dev spent the last years of his life there, and blamed the Congress for country's partition, saying they did it for sake of power.