Jai Gangajal is a drama film based on political backdrop in Bankipur in Bihar where MLA Babloo Pandey(Manav Kaul) and his brother Dabloo (Ninad Kamat) run a jungle raj in their town Lakhisarai.The poor farmers have to finance their political party by selling their land.
Ramazkant Chowdhary (Kiran Kamararkar) appoints Abha Mathur IPS officer (Priyanka Chopra) as SP of that district. She is hard on the criminals but her mentor who expect her to be soft and helpful to everyone ,who is the home minister of the area .Her subordinates get encouraged by her brave acts to bring down the Jungle Raj.
B.N.Singh (Prakash Jha) a corrupt officer DSP, has been helping these two brothers using legal loopholes by corrupt ways filling his pockets with financial favours from them.
Dabloo kidnaps a teenage girl Sunita (Vega Tamotia) along with her brother Nagesh (Ayush Khedekar)who refuse to give their land to them after their father committed suicide. Dabool rapes and kills the girl by hanging her on the tree showing it's a suicide, leaving her brother behind.
Singh gets disturbed by this brutal crime and arrest Dabloo Pandey. The young brother of the girl is allowed to hang Dabloo by the belt on the tree to show as suicide.Thus the villagers who are frustrated kill the Sarpanch and the goondas as they are also corrupt.
Abha is unable to control these killings, tries to keep law and order to her best .Babloo attacks DSP Singh and injures him. He is in search of Nagesh who was instrumental in killing Dabloo is being hidden by Singh but manages to get him and put him in a gunny bag and hang him from the tree. Pandey gets arrested by Abha does ending of corruption and terror.