Is it permissible for a group of students to study among themselves in a circle in the mosque, and are there conditions for that?

There is no harm in a group of students studying together in a circle in the mosque, due to the education and encouragement it provides, as long as none of them fear showing off. In fact, recitation in the manner described may be desirable, for the Prophet, peace and blessings be upon him, said: "No people gather in one of the houses of Allah, reciting the Book of Allah and studying it among themselves, except that tranquility descends upon them, mercy envelops them, angels surround them, and Allah mentions them among those with Him."