Realme has just begun the release of the September 2021 OTA update for Realme C12. This update brings only noticeable improvements in the system, display and phone manager.
Recently the device also got the August 2021 Security Patch so we can say this update, carries the same August 2021 Security Patch with Minor Improvements in the system.
Realme C12 released on 14th of August,2020 with Android 10 out-of-the-box.
Realme C12 got its android 11 update with Realme UI 2.0 this year in July.

Source: Realme Community
>>> update released on 23rd September 2021
| Android OS | Update | Release Date/Status | Estimated Months |
| Android 10 | Out-of-the-box | August 2020 | Nil |
| Android 11 | First OS update | July 2021 | 11 months |
| Android 12 | Second/Last OS update | Eligible | Unconfirmed |
The Realme C12 was released with an Android 10 in August 2020. Therefore, Android 11 is its first major OS update.
Hence, it is eligible for the upcoming Android 12 update and it will be its second/last major OS update. However, it is still unconfirmed.
The Realme C12 Android 11 Update with stable Realme UI 2.0 has been released with the September 2021 security patch.
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