  Kagome lattice, made of corner-sharing triangles, provides an excellent
platform for hosting exotic topological quantum states. Here we systematically
studied the magnetic and transport properties of RMn6Sn6 (R = Tb, Dy, Ho) with
clean Mn kagome lattice. All the compounds have a collinear ferrimagnetic
structure with different easy axis at low temperature. The low-temperature
magnetoresistance (MR) is positive and has no tendency to saturate below 7 T,
while the MR gradually declines and becomes negative with the increasing
temperature. A large intrinsic anomalous Hall conductivity about 250
{\Omega}-1cm-1, 40 {\Omega}-1cm-1, 95 {\Omega}-1cm-1 is observed for TbMn6Sn6,
DyMn6Sn6, HoMn6Sn6, respectively. Our results imply that RMn6Sn6 system is an
excellent platform to discover other intimately related topological or quantum
phenomena and also tune the electronic and magnetic properties in future
studies.
