Yes, I spotted another photo last night Its official designation was 'Fiat War Office Design 1915 modified for railway use'. Designed in London, built in India on Fiat truck chassis using armour shipped out from Britain
Many armoured cars were made to run on railway tracks because their off-road (cross-country) performance was poor and railways are nice and smooth.
Every nation found railways useful for logistics so they wanted to protect the railway. And from the opposite side, attacking the railway meant your enemy couldn't use it. Consequently 'protecting the railway' seemed a legitimate duty. So, you could find yourself running along the tracks in your armoured car hoping to catch the enemy in the act of laying demolition charges or otherwise in range of your gun(s).
I can't imagine they were very effective. If I was a lightly armed saboteur I would hide until the armoured car had passed me by. If the tracks had already been blown up, the armoured car would not be able to repair the track, and could only retreat, and I (a lightly armed saboteur) would still not engage the armoured car. Perhaps these armoured cars were to give the impression of power.