Prayer: Position of the Followers Relative to the Imam
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 1459
If the follower is a man, it is recommended that he stand at the right-hand side of the imam. If the follower is a woman, it is recommended that she also stand on the right-hand side of the imam, but based on obligatory precaution, she must stand behind him at least to the extent that the place of her sajdah is in line with the place of his knees when he goes into sajdah. If the imam is a man and the follower is a woman, or if the followers are a man and some women, it is recommended that the man stand on the right-hand side of the imam and the woman or women stand behind the imam. If the followers are some men and one woman or some women, it is recommended that the men stand behind the imam and the women stand behind the men.