How to read the value from excel and use that value as Input on application on Tricentis Tosca?

On Tricentis Tosca, I have used Tbox->Excel Modules Given the Tbox define excel range->Given the start cell and end cell. But i don't know how to read that value from excel and use on Application using Tosca.

You should be able to save the Excel value to a buffer using the TBox Excel Range Manipulation module and then use that buffer value in later test steps.