Jamieson, Fausset and Brown on Jeremiah 52:23

23. on a side--literally, (on the side) towards the air or wind, that is, the outside of the capitals of the pillars conspicuous to the eye, opposed to the four remaining pomegranates which were not seen from the outside. The pomegranates here are ninety-six; but in 1Ki 7:20 they are two hundred on each chapiter, and four hundred on the two (2Ch 4:13). It seems there were two rows of them, one above the other, and in each row a hundred. They are here said to be ninety-six, but immediately following one hundred, and so in 1Ki 7:20. Four seem to have been unseen to one looking from one point; and the ninety-six are only those that could be seen [Vatablus]; or, the four omitted here are those separating the four sides, one pomegranate at each point of separation (or at the four corners) between the four sides [Grotius].