Step 1: For resistors in parallel, use the formula:
\[
\frac{1}{R_{\text{eq}}} = \frac{1}{R_1} + \frac{1}{R_2}
\]
Given: \( R_1 = 6 \, \Omega \), \( R_2 = 6 \, \Omega \).
\[
\frac{1}{R_{\text{eq}}} = \frac{1}{6} + \frac{1}{6} = \frac{2}{6} = \frac{1}{3}
\]
\[
R_{\text{eq}} = 3 \, \Omega
\]
Step 2: Verify: For identical resistors, \( R_{\text{eq}} = \frac{R}{2} = \frac{6}{2} = 3 \, \Omega \). Matches option (3).