Export summary and reports to xls format for gst returns

Is it possible to Export Summary Reports to Xls format for GST TAX Returns?

No. All exports are in TSV format. That way, you can import them into spreadsheets, word processing programs, or other type applications. TSV is the most universal format for such things. Excel will allow you to copy and paste contents of a TSV file directly into a spreadsheet. Or you can use the import function. See this Guide: https://guides.manager.io/10645.