To calculate the force in bolt R, we use the principle of static equilibrium. The total load \( P = 60 \, \text{kN} \) is applied at the center of the column. The bracket has two bolts, one at each side of the column, and the force is shared equally by the bolts, considering symmetry.
The horizontal distance between the points of application of the load is 100 mm. Since the load is applied symmetrically and the forces in the bolts are equal, the resultant force in bolt R is simply half of the total load:
\[
F_R = \frac{P}{2} = \frac{60 \, \text{kN}}{2} = 30 \, \text{kN}
\]
Thus, the resultant force in bolt R is \( \boxed{27} \, \text{kN} \).