On the front of the motherboard, we find:

Samsung KLMBG2JETD-B041 32 GB NAND Flash Memory

Samsung K4EHE304EC-AGCF ? 3 GB Memory layered over the Exynos 7870 chip

And on the back, we have:

Samsung Shannon 515 power management IC

Samsung Shannon 925 RF Tranceiver

Skyworks Multiband Power Amplifier SKY77656-11

There are also two empty areas. Maybe the same board is used for different versions of the J6 that require a different complement of chips?