Hadith.1186 - Imam Jafar ibn Muhammad Al-Sadiq عليه السلام said: "It is sufficient for you to recite like a whisper to yourself when you are with them (in congregation)."
If someone is praying with those who differ in practice and recites a verse of prostration but does not prostrate, they should bow their head as a gesture.
When the Imam says, "Sami' Allahu liman hamidah (Allah سبحانه وتعالى hears the one who praises Him)," those behind him should say, "Alhamdulillahi Rabbil 'Alamin (All praise is due to Allah سبحانه وتعالى, the Lord عز وجل of all worlds)" but in a low voice.
If the person is praying with them, they should say, "Rabbana laka al-hamd (Our Lord عز وجل, to You is the praise)."
