Nuclear ECRs have a salutary impact on the mechanism for information sharing by the technology suppliers as well as countering proliferation risks. These informal arrangements have established some export-related rules to improve coordination and inculcated some habits among the states that might otherwise be involved in the proliferation of sensitive technologies. The Nuclear ECRs, despite being outside the framework of established non-proliferation treaties, have helped institute some recognizable non-proliferation norms and best practices. To the extent that the regimes are essentially supplier cartels, they have successfully managed the issue of selective denials and controlled the supply of nuclear proliferation-sensitive technology. Fundamentally, these regimes address NPT member states, yet three Non-NPT NWSs need to have access for peaceful purposes to nuclear technology. However, these states have been criticized for building nuclear weapons, keeping in view that they didn‘t violate any international law (as they have never been part of NPT). The study investigates the various possibilities of mainstreaming these three states, acknowledging their market potential in the realm of civilian peaceful nuclear technology and their plausible role in the non-proliferation struggle. The primary element of discussion and analysis in this study is that there is a need to mainstream the Non-NPT NWSs and to evolve the criteria for including the Non-NPT NWSs in the Nuclear ECRs. The central proposition of this research states that the world has transformed since 1968, so the international community needs to modify the mechanisms of the regimes in order to accommodate new markets and explore new venues of policy making in order to comprehensively address the nuclear proliferation concerns. There is a possibility to mainstream them because some are emerging markets and others have the potential to become future markets. Furthermore, they have acquired nuclear weapons so it is imperative to prevent them from horizontal proliferation by implementing stringent measures on the export controls. The study investigates the policy recommendations for the global community to address the NonNPT-NWSs in the Nuclear ECRs. This research is cognizant of the dire need to mainstream the Non-NPT NWSs in the Nuclear ECRs. India, although is a non-member of the NPT, has been given the NSG waiver along with AG, MTCR and WA membership. This action has raised questions on the credibility of the Nuclear ECRs as this discriminatory step weakens the mechanism of these regimes. An analysis of the underlying dynamics of this exceptional treatment of India has evolved the debate of developing an approach based on criteria to address the Non-NPT NWSs in the Nuclear ECRs. This study encompasses an analysis of the emerging trends and the imperatives for setting up uniform criteria for all three Non-NPT NWSs and taking into loop all the states having nuclear weapon technology. This proposed solution will help counter the proliferation issues, especially that of horizontal proliferation. The research hypothesis was evidenced to be true in finding the correlation between the requirement of mainstreaming these states in the Nuclear ECRs and the debate on criteria-based approach.