  Single crystals of ${\rm Ce_2Re_3Si_5}$ and ${\rm Pr_2Re_3Si_5}$ have been
grown by Czochralski method in a tetra-arc furnace. Powder x-ray diffraction
confirmed that these compounds crystallize in the ${\rm U_2Mn_3Si_5}$-type
tetragonal crystal structure with space group $P4/mnc$ (No. 128). The
anisotropic physical properties have been studied comprehensively by measuring
the magnetic susceptibility, isothermal magnetization, electrical transport and
specific heat. The low value of magnetic susceptibility together with no
magnetic transition down to $2$~K gives evidence that the Ce-ions are in the
intermediate valence state in ${\rm Ce_2Re_3Si_5}$. On the other hand ${\rm
Pr_2Re_3Si_5}$ revealed a magnetic ordering at $9$~K. The sharp drop in the
magnetic susceptibility and a spin flip like metamagnetic transition, for
$H~\parallel~[001]$ in the magnetization plot of ${\rm Pr_2Re_3Si_5}$ suggest
an Ising-type antiferromagnetic ordering. Based on magnetic susceptibility and
isothermal magnetization data, a detailed crystal electric field (CEF) analysis
shows that degenerate ${J} = 4$ Hund's rule derived ground state of ${\rm
Pr^{3+}}$ ion splits into nine singlets with an overall splitting of $1179$~K.
The magnetic ordering in ${\rm Pr_2Re_3Si_5}$ is due to the exchange-generated
admixture of the lowest lying CEF energy levels. Heat capacity data reveal a
sharp peak at $9$~K, that confirms the bulk nature of the magnetic ordering in
${\rm Pr_2Re_3Si_5}$.
