Hi UmaMaheswara,
I believe most standard notations are supported to automatically import as DateTime attributes but if the value changes or it throws exceptions. You can use the parse with option in the excel importer and create a microflow using these functions: https://docs.mendix.com/refguide/parse-and-format-date-function-calls/
Documentation for the parse with: https://docs.mendix.com/appstore/modules/excel-importer/#parse-with