In 4/4 Western music—whether rock or jazz—the backbeat is usually played on beats 2 and 4. In 12/8, the backbeat often falls on the 8th-note counts of beats 4 and 10. Typical backbeat placement in 4/4 and 12/8 is notated as follows.
Education
The Fundamentals of 3/4 Rock
Where to Play the Backbeat