The population of Andhra Pradesh before the formation of Telangana as a separate state was 84,655,533 (2011 Census) and it then covered an area of 275,045 sq km. But now, the state is spread across 160,205 sq km and has a population of 49,378,776. Its neighboring states are Telangana, Tamil Nadu, Chhattisgarh, and Orissa. Rayalaseema is a semi-humid region of the southern part of Andhra Pradesh covering the four revenue districts of Chittoor, Kadapa, Ananthapur, Kurnool and Nellore District of Andhra Pradesh. The origin of the name Rayalaseema is variously explained. As per 2011 in India the population of tribes is 8.2%. In Andhra Pradesh 6.6% tribes population exists. In the state tribes are of two groups. One group is at presently across the hilly tract of the Deccan Plateau and by the rivers Godavari and Krishna. The second group is present along the extended areas between the river Krishna and Godavari. According to ST order Act 1976, there are 33 types of Tribes in 8 districts and other 50 lakh nomads are surviving. In overall of the state, in Coastal Andhra 5.96, in Rayalaseema 2.86 and in Telangana 8.87 Tribal population exist.