How can I record other than melody track notes using MIDI keyboard

You can record MIDI to the Soloist Track also:

With your MIDI keyboard connected and communicating with BIAB, click on the Record MIDI button and a new window will appear. You can select to record on either the Melody Track or the Soloist Track.

This also allows you to record two different MIDI Tracks and include them with a BIAB Style if the Style does not have instruments populating those tracks. If you are using a BIAB Style that does contain instruments of either or both the Melody Track and the Soloist Track, you can replace those instruments with your external MIDI device.

You can also record your external MIDI keyboard onto the Melody or Soloist Track and then save the recording as a Performance Track and move the Performance Track to the Audio Track, then move the Audio Track to any open Mixer Track and continue to use the Melody or Soloist Track for additional live recordings from your external Keyboard.

By bouncing a Performance Track or a combination of BIAB Style MIDI instruments or RealTracks, you can use this method to record a dozen or more tracks.

If your version of BIAB has RealBand, you can also record your MIDI Keyboard with that program.

I see, I just want to replace 1 bar in piano I don't like. I probably have to mute it and record to melody/soloist track

Oh, that's different.

You can edit the notes in the Melody (or Soloist) track with either the notation editor or the piano roll. Here it is done with the notation editor:

If you edit the MIDI in a piano track, you have to Freeze that track or it will be replaced each time the song is regenerated.

If the piano track is a RealTrack, you can’t fix it by editing the MIDI since that is only there for educational purposes. You would have to take the audio from that track and move it to a DAW where you could use Melodyne Editor to edit it.