<p>The sustainability indicators for designing a smart city in a developing country have been identified. Such a comprehensive UIF Index offers excellent possibilities for the States/UTs to rank the cities to identify prior-ity areas which demand action, facilitate peer learning, highlight data gaps, and promote healthy competition. UIF Index measures the progress achieved and distance to be covered by the cities in their journey towards meeting the targets. The core infrastructure elements in a Smart City include: adequate water supply, assured electricity supply, sanitation, including solid waste management, efficient urban mobility and public transport, affordable housing, especially for the poor, robust IT connectivity and digitalization, good governance, especially e-Governance and citizen participation, sustainable environment, safety and security of citizens, particularly women, children and the elderly and health and education. In the study three input criteria and four output criteria have been selected. The input criteria considered are mobility, economy, environment, society, energy. The output criteria considered are quality of life (QL), self-sustenance and economic prosperity. The methodology proposed has been adopted the determining the importance of criteria using fuzzy Analytical Hierarchy Process. Fuzzy Analytical Hierarchy Process (AHP) helps to get the relative weights for input and output criteria. Data Envelopment Analysis method was adopted to estimate the relative efficiency. Assurance region (AR) model was adopted to avoid the zero effect.It is found that the relative efficiency for economic development (0.85) needs to be concentrated upon followed by energy (0.82), environment (0.81) and basic amenities (0.80) for designing and developing a smart city.</p>