One of the major demands or goals of some Native American activists in the 1960s and 1970s was for more self-determination and self-government. This was not their only demand as many of the more visible activists like those of AIM were pushing for an end to treaty violations and for improvements to Native American living conditions. The Self-Determination Act did not do those things.
But the Self-Determination Act did promote the idea of Indian self-government. It allowed them to have the opportunity to take control of the delivery of services that had previously been performed by agencies like the Bureau of Indian Affairs and the Indian Health Service. By doing so, it allowed the Indians more autonomy and control over their own affairs.
Public Law 93-638, or the Indian Self-Determination and Education Assistance Act of 1975, often referred to simply as the Indian Self-Determination Act, enacted authorization for the Secretaries of the Interior and of Health, Education and Welfare and some other government agencies to enter into contract with and make grants directly to federally recognized Indian tribes. This allows for the tribes themselves to have greater control in decisions regarding their own welfare rather than allocating the decision making to government officials.