קרא וטעה אפי' בדקדוק אות אחת מחזירין אותו: הגה וכן דין החזן הקורא ודוקא שנוי שמשתנה ע"י זה הענין אבל אם טעה בנגינת הטעם או בניקוד אין מחזירין אותו אבל גוערין בו: (ב"י ופסקי מהרי"א סי' קפ"א):

One who read and erred, even in the pronunciation of one single letter, we make [the reader] go back [and read again]. Gloss: The same law applies to the chazzan [i.e. the one who reads for others] who reads. And [this is all] specifically [in regards to] a change which alters the meaning [of the word], but if [the reader] erred in the melody of the cantillation or the vowelization [that does not alter the meaning], we do not make [the reader] go back, but we do rebuke [the reader]. (Beit Yosef and Piskei Maharia, Siman 181)

A place that has a minyan [a quorum of 10], but there is no one that knows how to read from the Torah according to its laws precisely and with the [correct] cantillation; nevertheless, they should read from the Torah with the blessings as per its laws. (And they conclude [i.e. read the Haftarah] from the Prophets. And see further in the beginning of Siman 144)