Hi @PRABA7385,
There is an advanced solution to rename a file including extension using REST API call. This offer many benefits:
- One only call, no need to create a new file and delete old one
- Creator and creation datetime can be preserved
- File keep same ID
Here a sample flow design to illustrate how to make it working:

- I use "Get file" properties to get "Link to item" which is the absolute URL to the file we'll need in the API request body.

- CurrentFileUrl expression: decodeUriComponent(first(split(outputs('Get_file_properties')?['body/{Link}'], '?')))
I split "Link to item"by '?' and take first item from resulting array. That way I've got the file absolute URL free of any URL parameters.
- NewFileUrl expression: replace(outputs('CurrentFileUrl'), outputs('CurrentExtension'), outputs('NewExtension'))
Here I made it simple for the example, stored the old and new extension then replace in the URL, but you can use the replacement method that best suits your needs.

- Here I build the request body with:
- srcPath: outputs('CurrentFileUrl')
- destPath: outputs('NewFileUrl')
- Note the available options:
- KeepBoth: Move file when false, copy file when true
- ResetAuthorAndCreatedOnCopy: Preserve source file creator/creation date when false, reset when true

- Method: POST
- Uri: _api/SP.MoveCopyUtil.MoveFileByPath()
- Headers:
| Accept |
application/json;odata=verbose |
| Content-Type |
application/json;odata=verbose |
- Body: outputs('HTTPRequestBody')
Results:


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