* A misspelling of a different word: It's possible you've made a typo. Could you double-check the spelling and see if it matches anything familiar?
* A specific regional dialect or term: "Tunkashila" might be a local or regional word with a specific meaning. If you provide context, such as where you encountered this word, it might be easier to understand.
* A fictional term: It's possible "Tunkashila" is a made-up word from a book, movie, or other creative work.
Please provide more information about where you encountered this word, or what you believe it might mean, so I can assist you further.