Answered by: Shaykh Ahmed Bin Mohamed Umarji
If I’m praying Taraweeh can someone who is not in namaz listen to me and when I get a mistake just cough to notify me I have made a mistake.?
In the name of Allah, the Most Gracious, the Most Merciful
If you accept the correction, your salaah and the salaah of all the followers will be invalidated.1
In this case, it would be best for them to identify you with the mistake after the completion of the two rakats.
Only Allah knows best
Written by Shaykh Ahmed Bin Mohamed Umarji
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham
1 Fatawa Darul Uloom Zakariyya, Volume 2, Page 514 , Raddu Al-Muhtar Volume 1, Page 622, Darul Fikr Beirut [ أوْ أخْذُ الإمامِ بِفَتْحِ مَن لَيْسَ فِي صَلاتِهِ كَما فِيهِ عَنْ القُنْيَةِ]