How does one greet a gathering that includes a scholar, a student of knowledge, and the general public?

Question:
If a person enters a gathering where there are scholars, students of knowledge, and the general public, and they are in the middle of a conversation, should he greet them and sit down, or should he go around and greet each one of them individually?

Answer:
In the name of Allah, the Most Gracious, the Most Merciful. Praise be to Allah, Lord of the worlds, and may Allah send prayers and blessings upon our Prophet Muhammad, and upon his family and all his Companions. As for what follows, there is no doubt that gatherings have etiquettes. If a person enters a gathering that is a session of knowledge and study, he should sit down and listen, and delay his greeting until after the session is finished. Likewise, if the gathering is a session of hadith, where one person is speaking and the others are listening, he should also sit down and not greet them until the speech is finished. However, if the conversation is distributed among the people sitting there, he should greet them upon entering in general, and specifically greet the one he wishes to greet individually.