GNU/Linux NetGear A6210 Wifi Driver Setup – Step-by-step Guide
Hi! The linked Tutorial shows you Step-by-Step How to Install NetGear A6210 Wireless Wifi/Bluetooth Driver in GNU/Linux Systems.
And the Netgear A6210 Driver for Linux is supported by the Mediatek MT7612U Kernel Module.
Especially relevant: this Driver is supplied from Linux 4.19 but some important Connection Issues has been fixed only starting from the 5.4.1 release.
So first provide to Update your system and then possibly see How to Install Latest Linux Kernel.
But on Debian-based it may be just missing the Proprietary Firmware!
In case to check your Adapter Chipset see: How to Check Wireless Device ID on GNU/Linux.
GNU/Linux Netgear A6210 Wireless Driver Installation Guide