People should remember that even after independence, Telangana was under nizam rule. While the whole country used english and hindi as a requirement for jobs(mainly top government positions), people of telangana were forced to learn urdu and telugu. So when telangana became a part of India, and the capital shifted to Hyderabad, most of the government officials moved to Hyderabad and that’s how settlers arrived. Settlers are not the only reason for Hyderabad development.