Determine the numerical value of the given expression: $\left(\frac{9^{3}}{6^{3}}\right)^{-1 / 3}$

Step 1 ：\(\left(\frac{9^{3}}{6^{3}}\right)^{-1 / 3}\)

Step 2 ：\(\left(\frac{729}{216}\right)^{-1 / 3}\)

Step 3 ：\(\left(\frac{216}{729}\right)^{1 / 3}\)

Step 4 ：\(\left(\frac{8}{27}\right)^{1 / 3}\)

Step 5 ：\(\frac{2}{3}\)