Aluminium billet and rod are ordered by alloy first, then by diameter and length. 6063 and 6061 behave differently in extrusion and machining, and the alloy also decides how the surface takes an anodised finish.
The second decision is the cut length and the end condition. A billet cut to the wrong length cannot be salvaged at the press, and the saw cut quality affects how it feeds. Confirm the length tolerance and whether the ends need to be square.
Then agree the packing, because aluminium marks easily and a bundle that has rubbed in transit arrives with surface damage that shows after finishing.
Send the alloy, diameter, length and quantity and we confirm the cut and packing arrangement.