Hi ,
You can use FM 'NUMBER_GET_NEXT' to get next available Number.
Check this one.
CALL FUNCTION 'NUMBER_GET_NEXT'
EXPORTING
nr_range_nr = '01'
object = nr_object
IMPORTING
number = l_number
returncode = returncode
EXCEPTIONS
interval_not_found = 1
number_range_not_intern = 2
object_not_found = 3
quantity_is_0 = 4
interval_overflow = 5.
Regards,
Deepika.