Bro, you can cast youtube video to tv or any other device if that device has youtube app installed. If your TV supports casting then you can cast audio, video, and pictures from your phone to tv and you can control playback from phone. you'll need to connect your phone to tv either via wifi direct or both devices on the same network...
Bro, almost all smartphone phone can cast videos from phone to tv. The thing which isn't supported on your phone could be Miracast which is different from DLNA
This is the app which I use for casting videos
BubbleUPnP for DLNA/Chromecast - Android Apps on Google Play
Stream all your music, videos and photos to various devices in your house:
• Chromecast, Chromecast Audio, Nexus Player, Nvidia Shield, and other Google Cast devices
• DLNA TVs and music receivers from popular TV and HiFi brands
• Xbox 360 and One, PlayStation 3 and 4(**)
• Amazon Fire TV and Fire TV Stick
• local Android playback