Catalyzes the C6-oxidation step in brassinosteroids biosynthesis (PubMed:12427982, PubMed:12445121). May convert 6-deoxoteasterone (6-deoxoTE) to teasterone (TE), 3-dehydro-6-deoxoteasterone (6-deoxo3DT, 6-deoxo3DHT) to 3-dehydroteasterone (3DT, 3-DHT), and 6-deoxotyphasterol (6-deoxoTY) to typhasterol (TY) (PubMed:12427982, PubMed:12445121). Involved in the organization and elongation of the leaf and stem cells (PubMed:12427982, PubMed:12445121). Not able to convert 6-deoxocastasterone (6-deoxoCS) and castasterone (CS) to brassinolide (BL) (PubMed:18656444). 6-deoxoteasterone + O2 + reduced [NADPH--hemoprotein reductase] = 6alpha-hydroxyteasterone + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] 6alpha-hydroxytyphasterol + O2 + reduced [NADPH--hemoprotein reductase] = H(+) + 2 H2O + oxidized [NADPH--hemoprotein reductase] + teasterone 3-dehydro-6-deoxoteasterone + O2 + reduced [NADPH--hemoprotein reductase] = 3-dehydro-6alpha-hydroxyteasterone + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] 3-dehydro-6alpha-hydroxyteasterone + O2 + reduced [NADPH--hemoprotein reductase] = 3-dehydroteasterone + H(+) + 2 H2O + oxidized [NADPH--hemoprotein reductase] 6-deoxotyphasterol + O2 + reduced [NADPH--hemoprotein reductase] = 6alpha-hydroxytyphasterol + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] 6alpha-hydroxytyphasterol + O2 + reduced [NADPH--hemoprotein reductase] = H(+) + 2 H2O + oxidized [NADPH--hemoprotein reductase] + typhasterol 3-dehydro-6-deoxoteasterone + 2 O2 + 2 reduced [NADPH--hemoprotein reductase] = 3-dehydroteasterone + 2 H(+) + 3 H2O + 2 oxidized [NADPH--hemoprotein reductase] 6-deoxoteasterone + 2 O2 + 2 reduced [NADPH--hemoprotein reductase] = 2 H(+) + 3 H2O + 2 oxidized [NADPH--hemoprotein reductase] + teasterone 6-deoxotyphasterol + 2 O2 + 2 reduced [NADPH--hemoprotein reductase] = 2 H(+) + 3 H2O + 2 oxidized [NADPH--hemoprotein reductase] + typhasterol Plant hormone biosynthesis; brassinosteroid biosynthesis. Expressed at low levels in all the tissues, but preferentially in the leaf sheath. Down-regulated by brassinolide (BL) in the brassinosteroid-deficient dwarf1 (brd1) mutant. Plants show a range of abnormalities in organ development and growth, with deficiency in the elongation of the stem and leaves, skotomorphogenesis, root differentiation and reproductive growth. Treatment with exogenous brassinolide (BL) rescues the abnormal phenotype. Belongs to the cytochrome P450 family.