The interplay between the nuclear activity and the interstellar medium (ISM) of galaxies plays an important role in their evolution: the gas accreting onto the dormant supermassive black hole turns it into an active galactic nucleus (AGN) and the ensuing activity is believed to starve the host galaxy of the fuel needed to form stars. The contribution of radio-loud AGN to this feedback effect is yet to be well understood. In order to understand the impact of radio AGN, we need to study the jet-ISM interaction in detail at high spatial resolution and also cover a wide range of parameters such as age/morphology, radio power. I will present the recent results from sub-kpc scale studies of cold gas in the very central regions of radio galaxies. I will also detail how such studies, in combination with theoretical modelling, provide new insights into the morphology, kinematics and physical condition of gas directly impacted by the radio jets. This is a step forward in quantifying the impact of radio jets on the ambient ISM and thereby the evolution of their host galaxies.