| OAL | Oriental Aromatics Limited | 356.0 | 340.2 | 352.3 | 6.7K | 3.7 | | 1.05 | |
| OBCL | Orissa Bengal Carrier Limited | 53.89 | 52.00 | 53.11 | 1.5K | 0.11 | | 0.21 | |
| ODIGMA | ODIGMA CONSULTANCY SOLUTIONS LTD | 22.94 | 22.20 | 22.30 | 4.7K | -0.44 | | 1.93 | |
| OFSS | Oracle Financial Services | 11,395 | 9,937 | 10,843 | 3.4M | -8 | | 0.07 | |
| OILCOUNTUB | Oil Country Tubular Limited | 58.89 | 53.61 | 58.89 | 74.9K | 2.80 | | 4.99 | |
| OLAELEC | Ola Electric Mobility Ltd | 38.26 | 36.16 | 37.00 | 75.32M | 0.33 | | 0.90 | |
| OLECTRA | Olectra Greentech Limited | 1,345 | 1,314 | 1,318 | 209.9K | -28 | | 2.04 | |
| ONELIFECAP | Onelife Capital Advisors Limited | 38.90 | 37.00 | 37.16 | 10.1K | -0.12 | | 0.32 | |
| ONEPOINT | One Point One Solutions Limited | 55.70 | 53.60 | 54.07 | 1.59M | -0.17 | | 0.31 | |
| ONESOURCE | ONESOURCE SPECIALTY PHARMA LTD | 1,690 | 1,634 | 1,654 | 171.2K | -17 | | 1.03 | |
| ONGC | Oil & Natural Gas Corporation Limited | 254.2 | 252.0 | 252.4 | 9.1M | 0.5 | | 0.19 | |
| ONWARDTEC | Onward Technologies Limited | 294.4 | 280.1 | 291.5 | 113.8K | 6.8 | | 2.39 | |
| OPTIEMUS | Optiemus Infracom Limited | 622.3 | 599.4 | 615.6 | 193.6K | 0.1 | | 0.02 | |
| ORICONENT | Oricon Enterprises Limited | 55.97 | 53.51 | 54.81 | 32.7K | -0.08 | | 0.15 | |
| ORIENTPPR | Orient Paper & Industries Limited | 18.80 | 17.00 | 17.76 | 1.61M | 0.56 | | 3.26 | |
| ORIENTTECH | Orient Technologies Limited | 263.7 | 255.5 | 257.2 | 125.4K | -5.8 | | 2.20 | |
| ORISSAMINE | The Orissa Minerals Development | 3,733 | 3,636 | 3,649 | 5.1K | -103 | | 2.74 | |
| ORTEL | Ortel Communications Limited | 1.830 | 1.670 | 1.770 | 18.0K | 0.020 | | 1.14 | |
| OSIAHYPER | Osia Hyper Retail Limited | 3.100 | 2.880 | 3.010 | 430.8K | 0.050 | | 1.69 | |
| OSWALSEEDS | ShreeOswal Seeds And Chemicals Limited | 10.24 | 9.99 | 10.19 | 76.8K | 0.14 | | 1.39 | |
| OWAIS | Owais Metal and Mineral Processing Ltd | 99.85 | 96.10 | 99.00 | 7.1K | 0.05 | | 0.05 | |