The correct option is "Only one" because the Inter-State Council is the only body among the three that is established by the provisions of the Constitution of India, specifically under Article 263. The National Security Council and Zonal Councils, while influential in governance and coordination, are established by legislation and administrative decisions rather than direct constitutional mandate. This distinction is crucial for the UPSC Prelims as it tests candidates' understanding of constitutional provisions versus legislative frameworks, which is a fundamental aspect of Indian polity.