How to add a SubReport from a MainReport in rdlc.

Hi Vinoc4,

According to your description, you want to have an image "button" only for the last record in your report, and use this "button" to call a subreport. Right?

In Reporting Services, we can add a subreport into a report and set the subreport toggled by a report item in visibility setting. However, this report item can't be a dynamic textbox in a detail row, it should be a static one. Since you only want the subreport be called by the last record, we suggest you add a row out side of group, then set the subreport toggled by the textbox in the added row. We have tested this case in our local environment. It looks like below:

Reference:

Add an Expand/Collapse Action to an Item (Report Builder and SSRS)

If you have any question, please feel free to ask.

Best Regards,

Simon Hou