For a situation where an archer will shoot an arrow six times, the best coding term to use is for.
This is because a "for" loop is typically used when you know exactly how many times you want to iterate through a block of code. In this case, since Rupert wants the archer to shoot exactly six times, a "for" loop is appropriate.
Example in pseudocode:
for i from 1 to 6 do
shootArrow()
end for