Thittivasal begins with a self-immolation attempt by a young woman. This is Sembaruthi (Thanu Shetty), who belongs to Mullaipaarai, and she wants the collector to set right the wrong done to her people.
She and her tribe have been living on the mountains peacefully for ages, under the guidance of Mooppan (Nasser). However, trouble begins when a cop, a minister and a collector plot to take over the place for their by displacing them and sell it to an MNC.
With Mooppan and two youngsters, Muthu (Mahendran) and Kumaran (Kinni Vinod), standing against them, they resort to nefarious ways to bring them under control.
