Can .h264 container contain audio tracks?
I'm guessing you are using ‘.h264’ as a file extension to denote raw H.264 (AVC) video streams. In this case no, it's only a single video stream that can't include any other media streams inside it.
It wouldn't be much use on its own since a raw (demultiplexed) video stream can't be seeked (no index) and almost nothing will play it. You'd have to multiplex it together with any audio or other additional media streams into a container file (typically MP4 or MKV).
It's not common to store raw video streams without a container as standalone files. Typically they are used as an intermediate step when processing demultiplexed video and audio streams separately and deleted after use.
(The other possibility is it's just a badly-named AVC-in-MP4-container file, in which case yes you can put audio in it, but you should also rename it .mp4 to fix the confusion.)