Hi,
As per my understanding you can not change maximum number of records in report FMRP_RW_BUDCON. If double click on the records and select "search actual line item document" then
in background this program executed "RFFMLI_RW_BCS".
So you can run separately from se38 and there you can increase maximum number of line item.
or you can find some other reports
Regards,
mukesh