The basic injustice at the core of Gangvaa is the way the landed classes take advantage of ordinary village folk. Early on in the film, a work crew finds a pot full of gold coins, and a suitably mustache-twirling zamindar (Amrish Puri) confiscates them to add to his already massive wealth. Enter Gangvaa (Rajnikanth) to save the day; Gangvaa kills Zamindar and his goons. Gangvaa puts together a band of the men who had suffered under the Zamindar's tyranny. Together they hang out in the wilderness and perform Robin-Hood-esque raids for the sake of vigilante justice. At some point Jamna (Shabana Azmi) encounters Gangvaa and is smitten. Then a village girl accuses Gangvaa of rape, and Jamna is enraged – it is here that she gets down to find the truth. It turns out that the rape was actually done by a totally different guy named Gangvaa (Raza Murad), and righting this wrong wins Jamna back for our hero, but makes him a new set of enemies that he spends the rest of the film fleeing from. Also on his tail is a police inspector (Suresh Oberoi), who cannot allow vigilante justice in his district, no matter how noble the intention.
