Answer:
Al musalla is a temporary prayer place, there is no reserved authority, typically those well scholared in Islam will lead the prayer, however anyone can. No seats are reserved.
Explanation:
Asalam O Alaikum! ✌
There is a difference in a Musalla and a Masjid. Commonly a Masjid is a designated place built for Muslims to pray. While the whole earth is a masjid with the exception of unclean places most commonly we refer to a Masjid as a building where we go to pray. A Musalla is a temporary place to pray such as a home or an outside area. It's not defined as a Masjid.
If you are referring to seat of authority in the mosque anyone can lead the prayer however we usually let someone well rehearsed in Quran and Islam to lead it. There is no authority.
If you are referring to actual seats such as chairs, they are not really reserved but the elderly use them if they cannot perform prayer in the standard way.
