  We report the electric transport study of the three-dimensional topological
insulator TlBiSe$_2$. We applied a newly developed analysis procedure and
precisely determined two-carrier transport properties. Magnetotransport
properties revealed a multicarrier conduction of high- and low-mobility
electrons in the bulk, which was in qualitative agreement with angle-resolved
photoemission results~[K. Kuroda $et~al.$, Phys. Rev. Lett. $\bm{105}$, 146801
(2010)]. The temperature dependence of the Hall mobility was explained well
with the conventional Bloch-Gr{\"u}neisen formula and yielded the Debye
temperature $\varTheta_{\rm{D}}=113 \pm 14$~K. The results indicate that the
scattering of bulk electrons is dominated by acoustic phonons.
