Rice is a heavy user of nitrogen (N) fertilizers. In India, to feed the growing popu- lations, it has been suggested that N fertilizer consumption would need an increase of approximately 24 million tons in 2030 compared with 2022; the current total N fertilizer consumption (year 2022) is around 18.86 million tons [1,2]. India’s production of rice (milled rice) increased from 53.6 million tons in the fiscal year 1980–1981 to 120 million tons in the fiscal year 2020–2021 [3]. In soil, more than 40–50% of the applied N is lost through different mechanisms, such as ammonia (NH3) volatilization, denitrification to nitrous oxide (N2O) and dinitrogen (N2), leaching and runoff [4–6]. These losses not only reduce the yield and economic efficiency of applied N [7], but also cause grave environmental consequences [8,9]. Due to the expansion of cultivation areas, the introduction of new cultivars, and the use of chemical fertilizers, rice yield has increased during the past 50 years, keeping pace with the world’s population growth [10]. Nevertheless, the N use efficiency (NUE) of applied N is still low [11–13], which not only causes climate-change-related issues, air, and water pollution, but also causes increases in the cost of production, given the waste of N as a valuable resource [11,14]. Therefore, it is important to reduce the loss of N from agricultural land [11], and there is a need for more attention to the identification and performance of N-efficient genotypes. Rice is the key staple food for the world’s poorest and undernourished people living in Asia and Africa as they cannot afford—or do not have access to—nutritious foods [15]. In the next 20 years, the world population is expected to increase by about two billion, and in Asia alone, to increase by around half of the world population [16]. A report by the CGIAR System [17] notes that with the expected growth in population and income and a decline in rice acreage, global demand for rice will continue to increase from 479 million tons of milled rice in 2014 to between 536 million and 551 million tons in 2030, with little scope for the easy expansion of agricultural land or irrigation. Furthermore, rice is a semi-aquatic plant and generally grows under flooded conditions, which makes it unique [18,19]. Special difficulties in managing N arise from this preferred habitat, including significant losses of N to water. Numerous studies were conducted before the 21st century to improve rice nitrogen use efficiency (NUE) and yield [20–22]. Their findings showed that nutrient-efficient cultivars under field conditions can help design selection regimes and identify useful traits that are important for screening N-efficient genotypes. The knowledge of the genotypes’ traits that increase NUE can be combined with the best N management practices, which would help contribute to economically viable and environmentally sustainable systems globally [23]. Different levels of N input (low, medium, high) in experimental studies have shown that significant variability is present for the use, uptake, and utilization efficiency of N. Hence, these aspects are the main areas where researchers can evaluate the response of existing genotypes at various levels of N. A number of agronomic factors in crop growth cycles affect performance and overall NUE, including the optimum N rate, appropriate N source, and timing of N application [11]. Thus, the combination of N-efficient genotype development with the best management practices is therefore an important path for various stressed ecosystems around the world. It has often been shown that rice NUE, which integrates physiological and soil N supply capacities, decreases with increasing N supply in the soil [24]. To identify the appropriate breeding strategies, the germplasm must be evaluated for physiological variability in NUE [25], genotype interaction with N inputs, and different levels of N based on precise selection. Therefore, in the present study, we assessed the response of rice genotypes with different levels of N for several rice genotypes, where rice was fertilized with neem-oil-coated urea according to the regulatory requirements of India. Our experimental trials were based on the new idea of screening rice genotypes for a higher NUE. The main objectives were to: (i) evaluate the growth and yield components of rice genotypes under control versus half and recommended N supplies; (ii) investigate the differences between rice cultivars in terms of economic yield and harvest index; (iii) screen the rice genotypes based on the grain yield efficiency index.