Very few Android 6 phones received updates beyond 6.0.1. Check Settings > About Phone > System Update . If you can reach Android 7, 8, or 9, do it immediately.
Warning: This voids warranties and requires unlocking the bootloader. It also may break banking apps. will whatsapp work on android 6.0.1
The app still sends and receives messages reliably. However, you may experience slower load times and occasional lag when opening heavy media files compared to modern devices. Very few Android 6 phones received updates beyond 6