$sql8 = mysql_query("SELECT `orderlist_id`, `brandname`, `packsize`, `quantity`, `mrp`, `ourRate`, `Sum`,user_id,userName,`date` FROM `orderlist` WHERE `user_id`='$userid' AND `userName`='$usern' AND `date`>date_sub( current_date(),interval 3 month)");
No need to rename field, you can enquote field name with ` character (press key before 1 on keyboard)
I have removed = sign from query condition, so it will not display current date record, but it will only show last three month records.
What kind of monthly output you want.