I can add 2 languages "hindi" and "marathi" using language setting. But as you can see in the screen-shot, I can enable hindi spell check but not Marathi.
I'm currently on Version 74.0.3729.169 (Official Build) (64-bit) and I see your problem there mate. I'm afraid as far as I know, they don't support Marathi at the moment among many other languages for spell check, which also includes Gujarati, Punjabi, Malayalam, Bangla, et cetera among the Indian languages.
As for international, I tried Arabic, Filipino, Nepali.. and list goes on, for which they don't have a spell check support.
They do support Hindi, which is great!
Your available options are hence limited to lookout for a chrome extensions. I'll post in a link if I could find one for you!