this basically removes the unwanted tracks.
this is already coded but please make sure to download mkvtoolnix and place its directory in for example:-
"C:\Program Files\EXAMPLE.exe" (usually its at your main hard disk)

downloads:-
mkvtoolnix:- https://www.fosshub.com/MKVToolNix.html
mediainfo:- https://mediaarea.net/en/MediaInfo/Download

you can also do this with other release with multiple tracks
just follow these steps

Step 1:- download "MKVToolNix" then locate the programe and copy its directory
in here "C:\wherever it is.exe" (usually its at your main hard disk)

Step 2:- place it in some folder with 4 tracks ( jap, eng, signs and songs and full subs and it doesnt have to be 4 it can be more)

Step 3:- locate the track number of each track by using Mediainfo or mkvtoolnix (recommended)

Step 4:- replace -a !(track number) and -s !(track number) to remove it and ---default track (track number) to make it as a default track that is the full subtitles or it can be anything
so it should look something like this (-a ! is audio   -s ! is subtitle)


FOR /F "delims=*" %%A IN ('dir /b *.MKV') DO "C:\Program Files\EXAMPLE FOR STEP 1" -o "fixed_%%A" -a !EXAMPLE FOR STEP 4 -s !EXAMPLE FOR STEP 4 --default-track EXAMPLE FOR STEP 4 --compression -1:none "%%A"
PAUSE

when done right:-
FOR /F "delims=*" %%A IN ('dir /b *.MKV') DO "C:\Program Files\MKVToolNix\mkvmerge.exe" -o "fixed_%%A" -a !1 -s !2 --default-track 3 --compression -1:none "%%A"
PAUSE

incase if there are multiple audios and subtitles
just add a comma to -a !.,. and -s !.,. it wont apply to default tracks
FOR /F "delims=*" %%A IN ('dir /b *.MKV') DO "C:\Program Files\MKVToolNix\mkvmerge.exe" -o "fixed_%%A" -a !1,2 -s !3,4 --default-track 5 --compression -1:none "%%A"
PAUSE