SSRS Expression

Add total on Group by :

=SUM(MAX(Fields!RoundOff.Value,"LedgerVoucher"))

here LedgerVoucher is group name

Serial number on Group by :

syntax:

=RunningValue(<Grouped field>,CountDistinct,”<DataSet>”)

Example:

=RunningValue(Fields!LedgerVoucher.Value,CountDistinct,"SendingBillsDS")

Date Format : Monthname - year 

=FORMAT(Fields!ExpDate.Value, "MMM-yy")

Ex: Jan-23