Mannosyltransferase involved in outer chain elongation of asparagine-linked oligosaccharides of the type Man(9)GlcNAc(2). Adds the first alpha-1,6-mannose to the Man(8)GlcNAc(2) and Man(9)GlcNAc(2), but not Man(5)GlcNAc(2), endoplasmic reticulum intermediates (By similarity). Represents the first enzymatic event required for synthesis of outer chain mannose linkages on yeast secretory proteins. N-glycan outer chain epitopes play a crucial role in the host-fungal interaction, virulence, and host immune response such as interleukin synthesis or phagocytosis by neutrophils. Transfers an alpha-D-mannosyl residue from GDP-mannose into lipid-linked oligosaccharide, forming an alpha-(1->6)-D-mannosyl-D-mannose linkage. Is recycled between the trans-Golgi network and a late compartment of the endoplasmic reticulum. The conserved DXD motif is involved in enzyme activity. Results in a temperature-sensitive growth defect, cellular aggregation, loss of outer chain elongation of N-glycans, hypersensitivity to a range of cell wall perturbing agents, as well as to constitutively activated cell wall integrity pathway. Finally, leads to attenuated virulence in a mouse model of systemic infection and affects inflammatory response and the efficiency of neutrophil phagocytosis by the host. Belongs to the glycosyltransferase 32 family.