RTSP h.264 in google chrome browser
Direct RTSP streaming is still not supported by browsers, if you have to play an RTSP stream in the browser then you need a proxy server that will convert RTSP to HTTP stream.
Many open source projects are there that will do the work of RTSP to HTTP conversion or you can use FFmpeg (used by VLC) to convert RTSP to HTTP and then can stream it on the browser.
These guys put together an rtsp over websocket player.https://github.com/Streamedian/html5_rtsp_player
But it does require a server to create the connection and parse the rtsp info (they include an easy to install package to take care of that).
And it doesn't support h265.
As other mentioned you cannot play RTSP natively on any browser. If your source is strictly RTSP then you can use a proxy server between your RTSP server and browser. You can use WebRTC proxy server to play RTP on WebRTC compliant browsers. http://webrtc.live555.com/