This paper analyzes the role of informal social networks in technology diffusion in a caste-based society in which a social hierarchical structure is prevalent. Often, information and technology diffusion are constrained by social and economic boundaries. In a complex and hierarchical social system in which caste plays a very decisive role in everyday life as well as in the political and policy fabric of the regional, state, and national system, proper targeting and dissemination of technology to the marginalized sections of society are very important for their development. Taking diffusion of improved rice varieties as an example, we analyze whether technology diffusion is confined within caste-based social networks or whether technology can break caste boundaries and spread across social networks. We found that informal networks tend to concentrate within caste-based groups and hence observed significantly stronger social network within caste than across caste categories. Strong within caste network discourages hybrids but facilitates stabilized technologies such as improved varieties whereas strong across caste networks discourage adoption of older and traditional varieties. It is important to highlight that existence of stronger within as well as across caste networks for scheduled tribes (ST) facilitated these marginalized communities to adopt improved and hybrid varieties. Acknowledgement :