Keep holding reset and the power for another 30 seconds .
Before using software tools, try a "30-30-30" reset to clear the NVRAM: Hold the reset button for while powered on. Netgear R6300 Firmware Recovery Utility
Never attempt a recovery over Wi-Fi; it will almost certainly fail and cause further damage. Keep holding reset and the power for another 30 seconds
Use the Windows Command Prompt or a TFTP client (like Tftpd64 ) to upload the original .chk or .img firmware file. 2. Smart Wizard Utility Netgear R6300 Firmware Recovery Utility
If your R6300 (v1 or v2) is stuck with a blinking amber power light or is not assigning IP addresses, use these recovery paths: 1. The TFTP Command Method