Namakkal , Rasipuram , Thiruchengode , Palani , Dharapuram , Kangeyam , Avinashi , Omalur , Dharmapuri , Hosur , Sankagiri , Krishnagiri , northern Dindigul , western parts of Tiruchirapalli , Perambalur , Vellore and Villupuram . They are also sparsely distributed in Thanjavur , Madurai and Theni districts of