Linksys EA6900 Router
That router is just a router, it definitely has no modem in it. 
I personally have an EA6400, on fttc.
This is for CABLE connections, so if you're with Virgin Media or any of BT's Openreach Fibre offering this is for you.
ADSL require an built in modem, which this doesn't have.
However, you could connect your modem to the wan port of this on ADSL. However, I don't think you like having two routers running 
However, I do use my router with an Talktalk one, its quite simple, route an ethernet cable from the lan port of your normal ADSL router into the WAN (internet) port of the EA6900. On the ISP router, disable the WiFi so you can use the Linksys one without it interfering and eventually, setup the internet PPPOE settings on the ADSL router. On the Linksys router, set it up using DHCP (if using manual setup; auto should detect this on first time setup) (and not one of the other settings like PPPOE; as your ADSL modem is handling this).
When you're connecting from an router to router, please use an CAT6/7, anything with gigabit speeds should be ok, as I do have problems with the internet hanging when using and old 100mbps cat5. I replaced this with 10000 Base-T Ethernet, so my wiring is future proof; and no more hangs due to no more bottlenecks through cabling
If you don't like running two routers, then just get another one which has an in-built modem.
The reason I run two routers is simple, I want the Linksys down, and the Talktalk up so I have signal in my deadspots 
