In my opinion:
I. If we take Aurata ("The Golden One") to be a Latin word, then
a. Because the a in the middle is long, its syllable takes the stress. It is pronounced about like the "a" in the English "father".
b. The a at the end, in contrast, is short, and much more clipped, something like the vowel sound in the English "pot".
c. The initial au is a diphthong, prounouced about like the "ou" in the English "house".
d. Authorities maintain that the Latin r should to some extent be rolled or trilled. This is, however, widely neglected, especially in ecclesiastical Latin.
e. Authorities also maintain that the Latin t should be "crisper" or "less aspirate" than the English equivalent, but this very fine distinction is almost univerally neglected by native Anglophones.
Putting it together, we might represent the word as
ow-RRAH-ta
II. If on the other hand, we take Aurata to be an English word, then the initial diphthong is, as you know, usually pronounced more like AW than like the Latin OW, as in "auricle" . The stress is in the same place, and the r unrolled:
aw-RAH-ta
Hope this helps.