Can any one explain the process of adding excel file in C# and What are the requirements for that?
Is it necessary to install MS Excel in the system for using of Excel in C#
You can read data from Excel spreadsheet without having Excel installed, using ADO.Net. Here is a sample for how to do this.
However, your question is a little vague. Since you do not have Excel installed, which of these do you really want to do:
You may get more useful answers if you clarify.
From past experience I would suggest you use a dedicated component like Gembox or Aspose Cells for this purpose. Besides it being more straightforward, you don't need to have Excel installed and you won't have deployment and licensing issues.
SpreadsheetGear for .NET will let you use Excel files in any .NET application (Console app, WinForms, ASP.NET, etc...) without having Excel installed.
You can see live samples here and download the free trial here.
Disclaimer: I own SpreadsheetGear LLC