
Samsung Galaxy A5(2016)
The latest firmware for Samsung Galaxy A5(2016) (SM-A510S) is A510SKSS2CTJ1 with Android 7.0 (Nougat), released on November 16, 2020 for 1 region (CSC). Every official firmware build for SM-A510S, 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/A510SKSS2CTJ1
SM-A510S started on Android 5 and has received 2 major Android upgrades; it now runs Android 7.0 (Nougat). The newest build, A510SKSS2CTJ1, was released on November 16, 2020. No new build has appeared for 72 months, so regular updates for this model have most likely ended.
Specifications of SM-A510, a regional variant of the same device. Chipset and SIM lines are left out: they can differ by region.

SM-A185G

SM-A185F

SM-A077F

SM-A085F

SM-A085M

SM-A276B

SM-A576U

SM-A566U
The newest firmware for SM-A510S runs Android 7.0 (Nougat): build A510SKSS2CTJ1, released on November 16, 2020.
The latest build for SM-A510S, A510SKSS2CTJ1, was released on November 16, 2020 (5 years ago).
SM-A510S has had no new firmware for 72 months, so regular updates have most likely ended.
Yes, all firmware files for SM-A510S are 100% official, original, and obtained directly from Samsung servers.
To flash SM-A510S, 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-A510S.