Catalyzes the transfer of sulfate to position 6 of galactose residues of keratan. It has a preference for sulfating keratan sulfate, but it also transfers sulfate to the unsulfated polymer. The sulfotransferase activity on sialyl LacNAc structures is much higher than the corresponding desialylated substrate, and only internal galactose residues are sulfated. It also may function in the sulfation of sialyl N-acetyllactosamine oligosaccharide chains attached to glycoproteins. It participates in