| Abbreviation | Definition |
|---|---|
| RIR | Reportable Item Report |
| RIRB | Response Input Ring Buffer |
| RIRG | Read Inter- Record Gap |
| RIS | Remote Installation Server |
| RIS | Radiological Information System |
| RIS | Reporting Identification Symbols |
| RIS | Research Information System |
| RIS | Regulation Impact Statement |
| RISA | Rapid Imaging Spectrophotometric Array |
| RISC | Reduced Instruction Set Computing |
| RIT | RadioImmunoTherapy |
| RIT | Request for Interface Tool |
| RITA | Radiofrequency Interstitial Tumor Ablation |
| RITA | Retail Innovation Technology Award |
| RITC | Regional Irrigation Training Camp |
| RITES | Rail India Technical and Economic Services |
| RITES | Railway Infrastructure Technical & Economic Services |
| RITF | Rat Infested TreFoil |
| RIU | Remote Interface Unit |
| RIV | Recirculation Isolation Valve |
| RJ | Right Justify |
| RJ | Radius of Jupiter |
| RJC | Reaction Jet Control |
| RJD | Rashtrya Janta Dal |
| RJD | Reaction Jet Device |
| RJD | Reaction Jet Driver |
| RJDA | Reaction Jet Driver Aft |
| RJP | Realistic Job Preview |
| RL | Register List |
| RLA | Register Linear Address |
| RLA | Residential Life Assistant |
| RLA | Registered Landscape Architect |
| RLC | Residence Life Coordinator |
| RLD | Rashtriya Lok Dal |
| RLEGS | Rural Landless Employment Guarantee Scheme |
| RLG | Reshall Linux Geek |
| RLL | Right Lower Limb |
| RLM | Rashtriya Loktantrik Morcha |
| RLN | Recurrent Laryngeal Nerve |
| RLO | Returned Letter Office |
| RLO | Resident Liaison Officer |
| RLP | Refill Light Pen |
| RLP | Registered Lighting Practitioner |
| RLP | Reactive Liquid Polymer |
| RLQ | Right Lower Quadrant |
| RLRC | Rose Lake Research Center |
| RM | Regional Manager |
| RM | Resident Magistrate |
| RM | Recovery Manager |
| RM | Redundancy Management |