  The cessation of AGN activity in radio galaxies leads to a remnant phase
during which jets are no longer sustained, but lobes can be detected for a
period of time before they fade away due to radiative and dynamical energy
losses. The time-scale of the remnant phase and AGN duty cycle are vital to
understanding the evolution of radio galaxies. In this paper, we report new
band-3 observations with the upgraded Giant Meterwave Radio Telescope (uGMRT)
for five remnant radio galaxies. Our uGMRT observations reveal emission of
low-surface-brightness in all five remnants with 400 MHz surface brightness in
the range of 36$-$201 mJy arcmin$^{-2}$. With band-3 uGMRT observations, we
discover wing-shaped radio morphology in one of our sample sources. Using radio
observations at 150 MHz, 325 MHz, 400 MHz, and 1.5 GHz, we model the radio
spectral energy distributions (SEDs) of our sample sources with the continuous
injection-off model (CI$_{\rm OFF}$), that assumes an active phase with
continuous injection followed by a remnant phase. We obtain total source ages
($t_{\rm s}$) in the range of 20.3 Myr to 41.4 Myr with $t_{\rm OFF}$/$t_{\rm
s}$ distributed in the range of 0.16 to 0.63, which in turn suggests them to
belong to different evolutionary phases. We note that, in comparison to the
remnants reported in the literature, our sample sources tend to show lower
spectral ages that can be explained by the combined effects of more dominant
inverse Compton losses for our sources present at the relatively higher
redshifts and possible rapid expansion of lobes in their less dense
environments.
