No need to delete unwanted languages/subtitle streams - open mkvmerge\file\header editor, then load the file into it, and change the default behaviour there and save - done in seconds. No need to remux or save to another file. Language streams will still be there, but your player should honour the default setting, playing the file in your language of choice.
EDIT sorry kaur - didn't realise that your tv is set to a chosen language and that's why you want to delete. Might be worth a try anyway, see what happens when you change the default setting of the file.