RTSP is a protocol for real-time streaming. You can transfer any data in any format, including text, audio, video, presentation ... bricks ... without considering that you can RTSP-it.
The basic idea is that when you open a new streaming session, you must DESCRIBE your streaming content to the client with an SDP (Session Description Protocol) response . There you say: "my content is video, it has N FPS, uses this codec, these are the necessary parameters for decoding the image ...", so the client can determine whether it can play stream data.
A streaming server does not need MP4, MPEG2 or any other container format ... as long as the server can open the container file, it can transfer its contents via RTSP.
So your question should be: "Is this version of the RTSP server in MP4 format implemented?"