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H{\sc i} absorption studies of active galaxies enable us to probe theircircumnuclear regions and the general interstellar medium, and study the supplyof gas which may trigger the nuclear activity. In this paper, we investigatethe detection rate of H{\sc i} absorption on the nature of radio galaxies basedon their emission-line spectra, nature of the host galaxies based on the\textit{WISE} colours and their radio structure, which may help understand thedifferent accretion modes. We find significant difference in distributions ofW2$-$W3 colour for sources with H{\sc i} absorption detections andnon-detections. We report a high detection rate of H{\sc i} absorption in thegalaxies with \textit{WISE} infrared colours W2$-$W3 $>$ 2, which is typical ofgas-rich systems, along with a compact radio structure. The H{\sc i} detectionrate for low-excitation radio galaxies (LERGs) with W2$-$W3 $>$ 2 and compactradio structure is high (70.6$\pm$20.4 \%). In HERGs, compact radio structurein the nuclear or circumnuclear region could give rise to absorption by gas inthe dusty torus in addition to gas in the interstellar medium. However, higherspecific star formation rate (sSFR) for the LERGs with W2$-$W3 $>$ 2 suggeststhat H{\sc i} absorption may be largely due to star-forming gas in their hosts.LERGs with extended radio structure tend to have significantly lower values ofW2$-$W3 compared to those with compact structure. Extended radio sources andthose with W2$-$W3 $<$ 2 have low H{\sc i} detection rates.

HI absorption towards low luminosity radio-loud AGNs of different accretion modes and WISE colours