Hi,
There is no way to assign the datasource at the folder level in SSRS.
Hi Mayooran99,
According to your description, you want to set data source at folder level, right?
In Reporting Services, if you want to design a report, you need to create a data source so that you can connect to the database. In you scenario, if you want to create a data source at the folder level, it cannot be achieved currently in Reporting Services. It is because data source is meaningful only for the report level. For your requirement, you can use a shared data source for each report. For more detail information, please refer to the link below:
Create, Delete, or Modify a Shared Data Source (Report Manager)
If you have any other question, please feel free to ask.
You could write some custom code in .NET, PowerShell, etc. to work against the ReportService2010 API.
https://msdn.microsoft.com/en-us/library/reportservice2010.reportingservice2010.aspx?f=255&MSPPError=-2147217396
More specifically, look at the SetItemDataSources method
https://msdn.microsoft.com/en-us/library/mt213551.aspx#M:ReportService2010.ReportingService2010.SetItemDataSources(System.String,ReportService2010.DataSource[])