
Samsung Galaxy Note 10.1 2014 Edition
The latest firmware for Samsung Galaxy Note 10.1 2014 Edition (SM-P605V) is P605VVRUDOH2 with Android 5.1.1 (Lollipop), released on August 30, 2015 for 1 region (CSC). Every official firmware build for SM-P605V, 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/P605VVRUDOH2
SM-P605V started on Android 4 and has received 1 major Android upgrade; it now runs Android 5.1.1 (Lollipop). The newest build, P605VVRUDOH2, was released on August 30, 2015. No new build has appeared for 135 months, so regular updates for this model have most likely ended.
Specifications of SM-P605, a regional variant of the same device. Chipset and SIM lines are left out: they can differ by region.

SM-P580X

SM-P610X

SM-P620

SM-P605L

SM-P605K

SM-P625

SM-P907A

SM-P905V
The newest firmware for SM-P605V runs Android 5.1.1 (Lollipop): build P605VVRUDOH2, released on August 30, 2015.
The latest build for SM-P605V, P605VVRUDOH2, was released on August 30, 2015 (11 years ago).
SM-P605V has had no new firmware for 135 months, so regular updates have most likely ended.
Yes, all firmware files for SM-P605V are 100% official, original, and obtained directly from Samsung servers.
To flash SM-P605V, 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-P605V.