Arbitration in India is founded on consent party autonomy and contractual privity under the Arbitration and Conciliation Act 1996. Traditionally only signatories to an arbitration agreement could be compelled to arbitrate disputes. However, contemporary commercial transactions increasingly involve complex corporate groups consortium arrangements and composite contracts where several entities participate in performance without formally signing the arbitration clause. This practical reality has compelled Indian courts to evolve doctrines that permit binding of non-signatories to arbitration agreements. This paper undertakes a doctrinal examination of the judicial development of non-signatory arbitration in India with particular focus on the Group of Companies doctrine, alter ego principle, agency, estoppel and composite transaction theory. The research critically evaluates this shift from strict privity to constructive consent through the lens of Section 7, Section 8, Section 11 and Section 16 of the 1996 Act together with the principles of separability and kompetenz kompetenz. It also examines the interaction of these doctrines with fundamental maxims such as pacta sunt servanda, qui facit per alium facit per se and substance over form. Comparative references to France, United Kingdom and Singapore are used to contextualize the Indian position. The paper argues that while judicial innovation has enhanced commercial efficiency and prevented multiplicity of proceedings it has also diluted traditional notions of consent and introduced doctrinal uncertainty. The study concludes that India has adopted a pro arbitration but court driven framework for non-signatory binding and recommends structured judicial tests and legislative clarification to ensure predictability fairness and alignment with international standards.