Hi Nira,
you can use file upload control of asp.net to upload your excel file and place it ata appropriate folder on shared location or on location which is in reach of your ssis ETL package. Now you need to pass path of this excel file to your package and then invoke it for execution.
You can refer this link
SSIS Package Integration with C# .NET[
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let me know if you have any further query
Regards,
Mubin