Offering Janazah prayer with the deceased's feet on the Imam's right side?
If, out of unawareness, the Janazah prayer of the deceased is performed in such a way that his feet are on the right side of the Imam and his head is on the left side, then the prayer is valid without any dislike (karahat). However, doing so intentionally is strictly disliked (makruh), but still, the Janazah prayer will be valid, and there will be no need to repeat it. (Kitab al-Nawazil / Vol: 6 / Page: 142)