how can we create more then one excel?
Assuming that by "more than one excel" you mean you want to create an XLS file with more than one sheet, org.apache.poi.ss.usermodel.Workbook has methods for adding sheets to an existing workbook. You may want to work through the examples in
http://poi.apache.org/spreadsheet/quick-guide.html to get a feel for the API.
and for apache POI will it support xls by converter? Will it display data upto 256th column in xls?
POI does not display anything, not does it know anything about any converters. It merely reads and writes files.
Or it needs office 2007 compulsory? Is there any other solution which can support both?
Office 2003 can work with XLS files, and Office 2007 can work with both XLS and XLSX files. POI itself does not need any version of Excel to be installed to do its work.