| OAL | Oriental Aromatics Limited | 334.4 | 327.0 | 327.9 | 15.3K | -6.2 | | 1.86 | |
| OBCL | Orissa Bengal Carrier Limited | 53.74 | 51.65 | 51.99 | 5.4K | -0.22 | | 0.42 | |
| ODIGMA | ODIGMA CONSULTANCY SOLUTIONS LTD | 25.39 | 23.49 | 23.49 | 111.1K | -1.23 | | 4.98 | |
| OFSS | Oracle Financial Services | 10,585 | 9,900 | 9,964 | 681.9K | -336 | | 3.26 | |
| OILCOUNTUB | Oil Country Tubular Limited | 56.95 | 54.15 | 55.00 | 22.3K | -0.31 | | 0.56 | |
| OLAELEC | Ola Electric Mobility Ltd | 42.88 | 39.65 | 41.49 | 326.11M | 2.25 | | 5.73 | |
| OLECTRA | Olectra Greentech Limited | 1,239 | 1,166 | 1,180 | 481.6K | -48 | | 3.89 | |
| ONELIFECAP | Onelife Capital Advisors Limited | 30.25 | 27.59 | 27.59 | 127.2K | -1.45 | | 4.99 | |
| ONEPOINT | One Point One Solutions Limited | 65.85 | 61.58 | 62.57 | 4.78M | -1.93 | | 2.99 | |
| ONESOURCE | ONESOURCE SPECIALTY PHARMA LTD | 1,888 | 1,772 | 1,825 | 604.5K | 34 | | 1.87 | |
| ONGC | Oil & Natural Gas Corporation Limited | 276.1 | 261.6 | 265.4 | 74.39M | -8.7 | | 3.16 | |
| ONWARDTEC | Onward Technologies Limited | 272.4 | 262.2 | 264.9 | 41.2K | -4.1 | | 1.52 | |
| OPTIEMUS | Optiemus Infracom Limited | 418.9 | 402.6 | 405.3 | 85.9K | -8.1 | | 1.95 | |
| ORICONENT | Oricon Enterprises Limited | 66.70 | 62.75 | 64.83 | 212.3K | 0.79 | | 1.23 | |
| ORIENTPPR | Orient Paper & Industries Limited | 18.35 | 17.85 | 18.17 | 247.5K | 0.34 | | 1.91 | |
| ORIENTTECH | Orient Technologies Limited | 271.9 | 265.0 | 266.8 | 368.3K | -16.0 | | 5.66 | |
| ORISSAMINE | The Orissa Minerals Development | 4,188 | 4,071 | 4,098 | 4.0K | -30 | | 0.72 | |
| ORTEL | Ortel Communications Limited | 1.640 | 1.540 | 1.600 | 5.5K | 0.010 | | 0.63 | |
| OSIAHYPER | Osia Hyper Retail Limited | 3.830 | 3.640 | 3.640 | 3.02M | -0.190 | | 4.96 | |
| OSWALSEEDS | ShreeOswal Seeds And Chemicals Limited | 11.28 | 10.81 | 11.00 | 103.5K | 0.07 | | 0.64 | |
| OWAIS | Owais Metal and Mineral Processing Ltd | 128.5 | 128.5 | 128.5 | 17.0K | -6.8 | | 4.99 | |