We used to use TextRange.findText() API to find the text in the specified TextRange in the forward direction and passing in a parameter "-1" to the API i.e TextRange.findText(<some_text_to_find>, -1) we were able to find the Text in the reverse direction for IE<11 in our solutions.
Since TextRange has been deprecated in IE11, is there any other alternate API for TextRange.findText() that could be used with Range object that would provide the same functionalities as TextRange.findText()