congregational zikr

Q: Is there any basis in the Shariah for congregational Zikr either in loud or silent form?

Q:

1. I would like to request the hukm of jahri and congregational zikr in the Masjid. One person initiates it and the rest repeat after him.

2. What is the recommendations of Hadhrat Maulana Thanwi (Rahimahullah) in this regards?

Q: I just want to know if loud zikr in a congregation is permissible because some say it is and some say it's bida. Please give me an explanation. Didn't our beloved prophet (Sallallahu Alayhi Wasallam) or those around him practice this kind of zikr?