How many boxes are kept between the vacant shelf and Box F?

The number of boxes kept above the Box K is the same as that of below the Box K. Box K is kept at an odd numbered shelf. Only one box is kept between K and H which is kept at even numbered shelf. From the above condition, there is only one possibility Box F is adjacent to Box H. Box I is kept on an odd numbered shelf. Box I is not kept below the vacant shelf. The number of boxes kept between the box G and F is same as the number of boxes kept between F and J. G’s shelf number is a multiple of 2. From the above condition, case1 was dropped. Case-2 shows the final arrangement.