The Rebbe clarifies the halachic requirement for Chazaras HaShatz, ruling that if six people have not yet prayed, the full repetition is performed. He explains a typographical error in the Sha'arei Teshuva and emphasizes the importance of the three daily study quotas of Chumash, Tehillim, and Tanya.
https://www.torahrecordings.com/rebbe/igroskodesh/016/006/6086