| NIRS | National Indigenous Radio Service 
| Others |
| NIRS | National Information and Reporting System
| Others |
| NIRS | National Information Resources Service
| Others |
| NIRS | National Institute of Radiological Science
| Others |
| NIRS | National Institute of Radiological Sciences
| Others |
| NIRS | National Institute on Retirement Security
| Others |
| NIRS | Near Infra Red Spectroscopy
| Others |
| NIRS | Near Infrared Reflectance Spectroscopy
| Others |
| NIRS | Noise Integrated Routing System
| Others |
| NIRS | Non Increasing Returns to Scale
| Others |
| NIRS | Non- Invasive Research System
| Others |
| NIRS | Non-Increasing Returns to Scale
| Others |
| NIRS | NTNU International Researcher Support
| Others |
| NIRS | Nuclear Information and Resource Service
| Others |