
Samsung Galaxy On7 Prime
The latest firmware for Samsung Galaxy On7 Prime (SM-G611S) is G611SKSU3CUD2 with Android 9 (Pie), released on May 24, 2021 for 1 region (CSC). Every official firmware build for SM-G611S, newest first: one row per build with all regions (CSC) that received it.
Each firmware build has its own page at https://samfirm.shop/build/{PDA}, where {PDA} is the build number from the list above. Example: https://samfirm.shop/build/G611SKSU3CUD2
SM-G611S started on Android 8 and has received 1 major Android upgrade; it now runs Android 9 (Pie). The newest build, G611SKSU3CUD2, was released on May 24, 2021. No new build has appeared for 66 months, so regular updates for this model have most likely ended.

SM-G611L

SM-G610S

SM-G615FU

SM-G6200

SM-G715A
The newest firmware for SM-G611S runs Android 9 (Pie): build G611SKSU3CUD2, released on May 24, 2021.
The latest build for SM-G611S, G611SKSU3CUD2, was released on May 24, 2021 (5 years ago).
SM-G611S has had no new firmware for 66 months, so regular updates have most likely ended.
Yes, all firmware files for SM-G611S are 100% official, original, and obtained directly from Samsung servers.
To flash SM-G611S, you need to download the appropriate firmware, put your device into Download Mode, and use the Odin tool to load the BL, AP, CP, and CSC files.
Downgrading is only possible if the bootloader version (binary bit) of the old firmware matches the current one. Always check the binary version before flashing SM-G611S.