Answer
$(5,6,2),(5,8,1),(3,6,1),(3,8,1),(3,6,2),(5,8,2).$
Work Step by Step
If the opposite vertices of a rectangular box are: $(a,b,c)$ and $(x,y,z)$ then the other six vertices will have coordinates(because the other $6$ vertices must "inherit" each coordinate from either of the opposite vertices): $(a,b,z),(a,y,c),(x,b,c),(x,y,c),(x,b,z),(a,y,z).$
Hence here the other vertices are: $(5,6,2),(5,8,1),(3,6,1),(3,8,1),(3,6,2),(5,8,2).$