Seven people, 1, 2, 3, 4, 5, 6 and 7 are sitting in a straight line, facing North. Only two people sit to the left of 1. Only three people sit between 5 and 1. 4 sits at one of the extreme end. 7 sits to the immediate right of 4. 3 sits in the middle of the row. 2 is not the immediate neighbor of 3. What is the position of 6 from right extreme end?