Is there any support for Netgear R6700v3? I have installed and using DD-WRT Kong Mod for NETGEAR R6700V3 (2018-09-23). However, I lost USB port of the router. Does OpenWrt support R6700v3 and does it have support for USB?
What does https://openwrt.org/toh/start?dataflt[Model*~]=R6700 say?
According to http://en.techinfodepot.shoutwiki.com/wiki/Netgear_R6700_v3 it comes with wireless cards which both aren't supported, which doesn't make it an attractive target for OpenWrt. Broadcom ARM combined with NAND flash isn't exactly easy either (due to unfortunate bootstrap choices made by Broadcom to require parts of the proprietary bootloader in the uploaded firmware image).
Would it be possible to support this device, yes - but you'd probably have to do the porting yourself - and the WLAN situation isn't likely to ever improve.
 the answer is no, it's not supported
 and in all likeliness never will be
 beyond very basic support via b43, which is limited to 802.11g (54 MBit/s at most) and doesn't provide support for 802.11n or 802.11ac data rates
thank you for the response. Could you then recommend the router that can be supported by DD-WRT and also have USB so I can share the printer on network?
That depends on your requirements and WAN speed, devices differ a lot.
Personally, with unspecified requirements, I'd look at ipq40xx or ipq806x based devices first, but depending on your needs, there may be cheaper or better options (beyond ~350-400 MBit/s WAN speed).
I currently have 200/200 verizon service and bunch of devices at home that need to wifi connection. Plus one gamer which is connected to Ethernet. Also, i need to be able to share the printer so kids can print their school work from laptops instead of running to PC were the USB printer is plugged in. In addition I am on the budget. What is your view of TP-Link AC1750 Smart WiFi Router - Dual Band Gigabit Wireless Internet Router for Home, Works with Alexa, VPN Server, Parental Control&QoS (Archer A7)?
The Archer A7 has the same hardware as the Archer C7, both are not really sufficient for 200/200. ipq4018 based devices would be a better option for roughly the same price, considering your current throughput there isn't much headroom left beyond that (check the benchmarks linked to below), but it should work - ipq806x if you need more future safety margin.
If it is DD-WRT you want to run rather than OpenWrt, you would need to check DD-WRT's website and forums for suitable devices. Another alternative is FreshTomato which I believe also recently gained some support for the R6700v3 (and R6400v2).
I just need stable router with parental controls and USB printer support. Router that I do not need to reboot every morning and the one that does not slow down my 200/200 service. Any suggestions? looks like if flash any router with *WRT I loose things like parental control and USB support.
I'd like to see a firmware for the R6700v3 as well.