Self-advocacy—being able to state one's preferences, make one's own decisions, and direct the course of one's life—is a pillar of autonomy and democratic citizenship. For Indian adults with intellectual and developmental disabilities (IDD), the practice of self-advocacy is frequently limited by deeply rooted sociocultural norms, institutionalised barriers, and uneven access to inclusive schooling and support services. In this study, we examine the diverse barriers and enablers that condition self-advocacy in this group through a mixedmethods approach that blends quantitative measurements and qualitative inquiry. A culturally adapted Self-Determination Scale for Individuals with Intellectual and Developmental Disability (SDS-IDD) was constructed and tested across 100 linguistically and regionally diverse Indian adults. Participants also underwent a systematic Self-Advocacy Curriculum to establish decision-making skills, communication, rights awareness, and goalsetting. Quantitative pre- and postintervention data reflected statistically significant improvements in selfdetermination across all subscales (p < 0.01), with a substantial gain in the 21–30 years group. Simultaneously, qualitative data obtained through interviews and support by family, peer interaction, inclusive pedagogy, and culturally adapted teaching strategies. This underscores the urgent need for culturally adapted tools in the field of special education. The results underscore the essential significance of contextualising selfadvocacy interventions in the sociocultural environment of India and validate the potential of adults with IDD to develop autonomy if equipped with adequate tools and support. This study provides a basis for policy, educational practice, and further studies to enhance the dignity, rights, and inclusion of individuals with intellectual and developmental disabilities in India, instilling a sense of hope and optimism in the audience.