Realme released October 2021 Security Patch with build version RMX3265_11_A.15 for Realme C25Y, it will fix some known issues and improve system stability along with the OTG feature.
The On-the-Go feature is used mainly for sharing files or to attach pen drives, memory cards or other low power peripherals, like a keyboard & mouse. Surprisingly this feature is common in all devices in 2021 but turned off in this video before this update.
Previous Update: Realme C25Y: September 2021 Security patch
The update will be randomly pushed out to a limited number of users today and will have a broader rollout in a few days after making sure there are no critical bugs.
Realme C25Y was released on 30th September 2021 with Android 11, Realme UI 2.0

Source>>Realme community
The update is available via OTA with a staged rollout with OTA pushed to a limited number of users after making sure there are no critical bugs rest of the users get the update.
| Android OS | update | Released date/status |
| Android 11 | Out-of-the-box | June 2021 |
| Android 12 | First OS update | Eligible/unconfirmed |
| Android 13 | second Os update | – |
Realme C25Y was released with an Android 11 in September 2021. Therefore, Android 12 and Android 13 probably are going to be their first and second Major OS updates respectively, However, they are still unconfirmed.
The Realme C25Y security patch with stable Realme UI 2.0 has been released in batches. A wider rollout to all the users is expected.
Once the update is available on your device, you can head over to Settings >> About Phone >> Software Update section to update your Realme device with the latest update.
For more Realme Android updates please download our android app – available on the Play Store