| Abbreviation | Definition |
|---|---|
| R and D | Research and Development |
| R&D | Research and Development |
| R&M | Renovation and Modernisation |
| R.C.E. | Regional College of Education |
| R.P.E. | Railway Protection Force |
| R.S.D.P. | Ranjit Sagar Dam Project |
| RA | Return All |
| RA | Return Address |
| RA | Respect Authority |
| RA | Residential Assistant |
| RA | Resident Advisor |
| RA | Royal Armorer |
| RA | Residental Advisor |
| RA | Residential Advisor |
| RA | Royal Academician |
| RA | Registered Accountant |
| RAA | Residential Accredited Appraiser |
| RAA | Relative Azimuth Angle |
| RAAB | Remote Amplifier and Adaption Box |
| RAAB | Remote Application and Advisory Box |
| RAAD | Roll Attitude Anomaly Detection |
| RAAM | Roll Attitude Acquisition Mode |
| RAATE | Recovery Attitude and Treatment Evaluator |
| RAB | Risk Assessment Board |
| RABMN | Remote Area Business Message Network |
| RAC | Recruitment and Assessment Centre |
| RAC | Reliability Analysis Center |
| RAC | Risk Assessment Code |
| RACE | Recorded Activity Compared To Expectations |
| RACS | Rotation Axis Coordinate System |
| RACS | Reliability Action Center |
| RACT | Reasonably Available Control Technology |
| RACU | Remote Automatic Calibration System |
| RAD | Rapid Application Development |
| RAD | Reactive Airway Disease |
| RADAR | Radio Detection and Ranging |
| RADAR | Radio Detecting and Ranging |
| RADCC | Radiation Control Center |
| RADIUS | Remote Authentication Dial-In User Service |
| RAE | Radio Astronomy Explorer |
| RAF | Rapid Action Force |
| RAF | Royal Air Force (UK) |
| RAF | Requirements Analysis Form |
| RAFC | Regional Area Forecast Centre |
| RAFC | Regional Agricultural and Fisheries Council |
| RAG | Research Animal Holding Facility |
| RAHF | Roll Attitude Indicator |
| RAI | Retailers Association of India |
| RAI | Redundant Array of Inexpensive Disks |
| RAI | Radar Altimeter Indicator |