An industrial coolant system models the rate of heat dissipation, RRR (in kW), using the function R(w)=(12w−3)6\displaystyle R(w) = \left( \frac{1}{2}w - 3 \right)^6R(w)=(21w−3)6, where w w\,w is the flow rate of the liquid.
Determine the constant term in the binomial expansion of R(w)R(w)R(w).