Hello @Waqar Habib 

Go to report definition window. Search for the report you want to see the font. Click RMB and export layout (if you have multiple layout then go to detail window and export the one you need).

Open the layout with notepad and see the font information.

You can change it and upload back to application. But I believe that the font you want to use must be available on report forts window

Hope this helps