| OAL | Oriental Aromatics Limited | 288.3 | 282.0 | 283.9 | 3.6K | -2.2 | | 0.75 | |
| OBCL | Orissa Bengal Carrier Limited | 56.30 | 54.90 | 54.99 | 13.2K | -0.01 | | 0.02 | |
| ODIGMA | ODIGMA CONSULTANCY SOLUTIONS LTD | 31.99 | 31.25 | 31.41 | 9.5K | -0.33 | | 1.04 | |
| OFSS | Oracle Financial Services | 7,701 | 7,575 | 7,593 | 160.6K | -84 | | 1.09 | |
| OILCOUNTUB | Oil Country Tubular Limited | 62.30 | 58.00 | 58.72 | 46.5K | -1.85 | | 3.05 | |
| OLAELEC | Ola Electric Mobility Ltd | 45.87 | 41.70 | 43.58 | 298.89M | -0.35 | | 0.80 | |
| OLECTRA | Olectra Greentech Limited | 1,240 | 1,191 | 1,196 | 310.1K | -45 | | 3.60 | |
| OMFREIGHT | Om Freight Forwarders Ltd. | 91.40 | 89.12 | 90.63 | 46.3K | 0.49 | | 0.54 | |
| OMKARCHEM | Omkar Speciality Chemicals Limited | 6.200 | 5.900 | 5.900 | 2.8K | -0.240 | | 3.91 | |
| ONELIFECAP | Onelife Capital Advisors Limited | 16.64 | 15.80 | 16.60 | 6.7K | 0.59 | | 3.69 | |
| ONEPOINT | One Point One Solutions Limited | 54.56 | 52.34 | 54.20 | 1.24M | 0.97 | | 1.82 | |
| ONESOURCE | ONESOURCE SPECIALTY PHARMA LTD | 1,805 | 1,765 | 1,798 | 112.3K | 1 | | 0.08 | |
| ONGC | Oil & Natural Gas Corporation Limited | 242.4 | 238.1 | 241.9 | 10.83M | 3.8 | | 1.60 | |
| ONWARDTEC | Onward Technologies Limited | 305.9 | 292.6 | 296.0 | 27.0K | -10.0 | | 3.25 | |
| OPTIEMUS | Optiemus Infracom Limited | 508.1 | 499.3 | 504.3 | 70.0K | -6.7 | | 1.30 | |
| ORICONENT | Oricon Enterprises Limited | 60.00 | 58.70 | 58.99 | 48.3K | -0.99 | | 1.65 | |
| ORIENTPPR | Orient Paper & Industries Limited | 23.25 | 22.40 | 23.12 | 445.9K | 0.49 | | 2.17 | |
| ORIENTTECH | Orient Technologies Limited | 445.0 | 428.9 | 432.9 | 7.28M | -8.1 | | 1.83 | |
| ORISSAMINE | The Orissa Minerals Development | 5,229 | 5,025 | 5,040 | 14.9K | -5 | | 0.09 | |
| ORTEL | Ortel Communications Limited | 1.470 | 1.470 | 1.470 | 676 | -0.070 | | 4.55 | |
| ORTINLAB | Ortin Laboratories Limited | 14.30 | 13.07 | 13.32 | 3.9K | -0.38 | | 2.77 | |
| OSIAHYPER | Osia Hyper Retail Limited | 15.62 | 14.55 | 14.96 | 308.1K | -0.16 | | 1.06 | |
| OSWALSEEDS | ShreeOswal Seeds And Chemicals Limited | 16.89 | 16.32 | 16.45 | 64.3K | -0.53 | | 3.12 | |
| OWAIS | Owais Metal and Mineral Processing Ltd | 264.9 | 254.5 | 257.4 | 33.3K | -0.4 | | 0.16 | |
| OWAIS.SM | Owais Metal and Mineral Processing Inc. | 290.0 | 268.6 | 273.4 | 37.8K | -14.0 | | 4.85 | |