We start with the expression \( \sqrt[3]{x^{6} y^{9} z^{15}} \). To simplify this, we can express it as \( (x^{6} y^{9} z^{15})^{\frac{1}{3}} \).
Step 2: Simplify Each Term
Next, we apply the property of exponents, which states that \( (a^{m})^{n} = a^{m \cdot n} \). Thus, we can simplify each term:
\[
(x^{6})^{\frac{1}{3}} = x^{\frac{6}{3}} = x^{2}
\]
\[
(y^{9})^{\frac{1}{3}} = y^{\frac{9}{3}} = y^{3}
\]
\[
(z^{15})^{\frac{1}{3}} = z^{\frac{15}{3}} = z^{5}
\]
Step 3: Combine the Results
Combining these results, we have:
\[
\sqrt[3]{x^{6} y^{9} z^{15}} = x^{2} y^{3} z^{5}
\]
Final Answer
Thus, the simplified expression is:
\[
\boxed{x^{2} y^{3} z^{5}}
\]