Xiaomi has released MIUI 9 Global Stable ROM V9.6.4.0.NCCMIFD for Redmi 4A. The update comes with bug fixes, system improvements and optimisations. You’ll get the update automatically or you can download it manually.

The Redmi 4A is a budget smartphone launched in 2017 with Android 6.0 Marshmallow. It comes with a hybrid dual-SIM card slot, features a 5-inch HD (720×1280 pixels) display and runs on a powered by a 1.4GHz quad-core Snapdragon 425 SoC paired with the Adreno 308 GPU and 2GB of RAM.

Other improvements and optimizations
Fix – Simplified and Traditional Chinese had errors in OOB flow (08-15)
Fix – “Forgot password” was covered by other UI elements (08-15)
Fix – Updated Android Security Patch to 2018-07-01 (08-15)
Fix – Issues with big fonts (08-15)

System
Optimization – 
Improved system performance and overall stability (08-15)
For download links and instructions follow the link in the source below.