R6700 Accidentally shut down during firmware update and now can’t use the internet

What are the led's on it doing? 

Did you try a factory reset? Push and hold reset while powered on for 7-15 seconds.

If that doesn't help, you can try recoving it with tftp or nmrpflash.
are you on windows? if so, follow this guide
https://kb.netgear.com/000059634/How-to-upload-firmware-to-a-NETGEAR-router-using-Windows-TFTP
just make sure you enable tftp
https://www.thewindowsclub.com/enable-tftp-windows-10

and here's a video walk through using a tftp client. Use the built in one for windows 10 though. the video is more of an example of how its done.
https://www.youtube.com/watch?v=R9DLrLQrpaw

and if that doesn't work, you can try using nmrpflash
https://github.com/jclehner/nmrpflash