Prane,
The file format should be CSV. The mapping format what you created should sync with excel you are uploading.
Lets say if you have Status in Mapping format and Status in your excel, make sure that you give correct technical name and try.
Make sure that you give all the Mandatory fields required during the Load.
Make sure that you are selecting correct type in Mapping format for Business Partner, Leads, Activities based on the transaction you are performing
Durig the file attaching to ELM and Process, is it saying Mapping Successfull?.
Screenshot will help us determing correct solution for you.
