Hi @Rajendra Sonawane ,
Per my research and test, unfortunately, there is currently no REST API can get the comments which is newly added or removed.
As far as I know, we only can use the following REST API to get comments from SharePoint list item:
https://xxxx.sharepoint.com/sites/xxx/_api/web/lists/getbytitle('List_test')/items(10)/Comments
Hope it can help you. Thanks for your understanding.
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