We present the results from torque magnetometry studies of the kagome superconductor ${\mathrm{RbV}}_{3}{\mathrm{Sb}}_{5}$ under applied fields up to 45 T and temperatures down to liquid $^{3}\mathrm{He}$ temperature (0.32 K). The torque signal shows clear de Haas--van Alphen (dHvA) oscillations with eight distinct frequencies ranging from $\ensuremath{\approx}150$ to 3000 T. Among these, five are above 500 T. Angle-dependent measurement of dHvA oscillations shows that all frequencies follow 1/$\mathrm{cos}\ensuremath{\theta}$ dependence, where $\ensuremath{\theta}$ is the tilt angle with respect to the applied field direction, and the oscillations disappear above $\ensuremath{\theta}$ = ${60}^{\ensuremath{\circ}}$, which confirms that the Fermi surfaces corresponding to these frequencies are two dimensional. The Berry phase ($\ensuremath{\phi}$), calculated by constructing a Landau level fan diagram, is found to be $\ensuremath{\approx}\ensuremath{\pi}$, which strongly supports the nontrivial topology of ${\mathrm{RbV}}_{3}{\mathrm{Sb}}_{5}$. Using the Lifshitz-Kosevich formula, we estimate the effective mass (${m}^{*}$) of charge carriers in ${\mathrm{RbV}}_{3}{\mathrm{Sb}}_{5}$, and it is found to be heavier ($\ensuremath{\approx}0.7{m}_{o}$, where ${m}_{o}$ is the free electron mass) than that for other topological insulators. The findings of high frequencies up to 3000 T in ${\mathrm{RbV}}_{3}{\mathrm{Sb}}_{5}$ have not been reported previously, and the results regarding the Fermi surface of ${\mathrm{RbV}}_{3}{\mathrm{Sb}}_{5}$ are crucial for understanding the charge density wave order, superconductivity, and nontrivial topology in $A{\mathrm{V}}_{3}{\mathrm{Sb}}_{5}$ ($A$ = K, Rb, and Cs), as well as the interplay among them.