Step 1: Concept
Capacitors in series follow the reciprocal rule ($1/C_s = 1/C_1 + 1/C_2$), while capacitors in parallel add directly ($C_p = C_s + C_3$).
Step 2: Meaning
First, find the equivalent capacitance of the top branch (C1 and C2 in series).
Step 3: Analysis
For the series part: $C_s = (4 \times 8) / (4 + 8) = 32 / 12 = 2.66 \mu$F. Now, add the parallel capacitor C3: $C_{net} = 2.66 + 6 = 8.66 \mu$F.
Step 4: Conclusion
The net capacitance of the circuit is approximately 8.6 $\mu$F.
Final Answer: (A)