The design shear strength of a reinforced concrete rectangular beam with a width of $250 \: \mathrm{mm}$ and an effective depth of $500 \: \mathrm{mm}$, is $0.3 \: \mathrm{MPa}$. The torsional moment capacity of the section (in $\mathrm{kN} . \mathrm{m}$) under pure torsion, as per $\mathrm{IS} \: 456:2000$, is $\_\_\_\_\_\_\_\_\_\_\_$ (round off to one decimal place).
