Hi Karan,
for EBELN as (import) table parameter table you can use structure RANGE_EBELN or structure FRE_EBELN_RSTY. Better would be an IMPORT parameter of table type FRE_EBELN_RTTY, if you have no RFC fm.
For your output structure of internal report type T_EKPO you have to define a matching structure in SE10. If you want to avoid TABLES parameter, then you have to define a table type in SE10 for this structure, too.
Regards,
Klaus