  We report measurements of temperature dependent magnetic susceptibility,
resonant x-ray magnetic scattering (XRMS) and heat capacity on single crystals
of Tb1-xLaxRhIn5 for nominal concentrations in the range 0.0 < x < 1.0. TbRhIn5
is an antiferromagnetic (AFM) compound with TN ~ 46 K, which is the highest TN
values along the RRhIn5 series. We explore the suppression of the
antiferromagnetic (AFM) state as a function of La-doping considering the
effects of La-induced dilution and perturbations to the tetragonal crystalline
electrical field (CEF) on the long range magnetic interaction between the
Tb$^{3+}$ ions. Additionally, we also discuss the role of disorder. Our results
and analysis are compared to the properties of the undoped compound and of
other members of the RRhIn5 family and structurally related compounds (R2RhIn8
and RIn3). The XRMS measurements reveal that the commensurate magnetic
structure with the magnetic wave-vector (0,1/2,1/2) observed for the undoped
compound is robust against doping perturbations in Tb0.6La0.4RhIn5 compound.
