Enables N-acetylgalactosamine 4-sulfate 6-O-sulfotransferase activity. Acts upstream of or within several processes, including chondroitin sulfate biosynthetic process; post-anal tail morphogenesis; and skeletal system development. Predicted to be located in Golgi apparatus and membrane. Predicted to be integral component of membrane. Is expressed in several structures, including alimentary system; central nervous system; ear; heart; and skeletal system. Orthologous to human CHST11 (carbohydrate sulfotransferase 11). [provided by Alliance of Genome Resources, Apr 2022]