You must enable "Unknown Sources" in your phone's Settings > Security to run an APK file. Technical Requirements & Constraints About supported operating systems | WhatsApp Help Center
Navigate to whatsapp.com/android using your phone's browser. Tap to get the APK file. download whatsapp for android 6.0.1
Android 6.0.1 has limited RAM (usually 1-2GB). To prevent the app from crashing: You must enable "Unknown Sources" in your phone's
: Check if a newer Android version is available for your device by going to Settings > System > Software Update Google Help Do you need help transferring your chats from an old phone to this one? About supported devices | WhatsApp Help Center Android 6
As of late 2023/early 2024, WhatsApp has officially ended support for Android devices running OS versions older than 5.0. However, Android 6.0.1 is technically above the cutoff. If you are having trouble finding the app on the Google Play Store, it is likely because your device is considered "legacy" by modern app standards, or the Play Store version on your phone is outdated.