how to fit content of reports so that we can print it on A4 size
The only way to do this is to physically decrease the size of your report when building it as there is no auto size capability in report builder.
Right click and properties on the grey back ground. Then change the size and orientation as required.
Then click on the white body and ensure the properties bar is open. Expand the size properties option and set the size of your report to reflect the previous selection.
Also don't forget to set the margins as this will effect the amount of printable space on your report.
Lastly ensure you alter the size of you fonts and report parts to fit on the size required.
I'd love to see an automatic sizing feature in the report builder for exporting.