I am talking about two years ago in my sentences below.
Her people had fought a hard battle. In celebration, students had taken to the streets and placed carnations in the soldiers’ gun barrels.
Is it correct or do I need had placed?
It's correct, Moni. The single "had" governs all the actions that follow. It would even be correct to say, "In celebration, students had taken to the streets, danced, sung songs, exchanged presents, drunk wine and placed carnations in the soldiers’ gun barrels."