New technology based start-ups play a very important role in developing the economy of a country. However, product based B2B start-ups in India are rare and existing ones have to undergo several challenges in commercializing. Present study explores the evolution of technological capabilities that enable commercialization among such early stage start-ups by adopting a multiple case based (four independent start-ups) inductive methodology with Indian telecom start-ups as the context. We have identified architectural design, algorithmic implementation and product adaptation as components of technological capability of such start-ups. We explore the link between knowledge acquisition, telecom specific knowledge and capability evolution in present work in a regulated and knowledge intensive context. Finally, we put forth a three stage framework mapping the evolution of technological capabilities among telecom start-ups, as well as identify regulatory bodies, standard making bodies and social network as facilitators in the capability evolution process.