While Xiaomi usually keeps its smartphones up to date with new MIUI versions for many years, the same can't be said for Android version updates, especially for some low-end and lower-midrange phones. These are sometimes stuck on an older iteration of the OS, even if running the latest MIUI.
This, however, is no longer the case for the Redmi 7A. This low-end model was released last July, and it was already running MIUI 11, which is still the latest for most Xiaomi phones, even if MIUI 12 is already on the way to a few lucky ones.
Now though, the Redmi 7A is getting a new update in China which switches up the underlying Android version from 9 Pie to 10. It's still MIUI 11, mind you, that hasn't changed. The new software also brings a newer security patch level, May 2020. That's not current anymore, but for a low-end handset it's not bad.
The update arrives over-the-air as a 1.7GB download, and once you install it you'll be have MIUI 188.8.131.52 QCMCNXM.
Hopefully the international Redmi 7A models will receive a similar update soon.