Determining how many records were read and processed in a MailStream Plus Name-Address input file and the type of presort information they had.

MailStream Plus™- all versions, all platforms
To see the MailStream Plus™ (MSP) statistics for the input Name-Address file, there is a section called 'Control Totals' in the MSRPRPT output file (commonly called the 'RPT' report.)  
The location of the RPT output file can be determined by looking for where the MSRPRPT will be written to: 
On z/OS in the job's JCL for the job.
On Windows in the .bat for the job.
On UNIX/Linux in the .job for the job
On IBMi the MSRPRPT report is the PRNTRPT output Spool File. 

That output file starts with a section listing all of the job's parameters.  And following that is a section called 'Control Totals'.  It looks similar to this-
MSST00A-- MailStream Plus Statistics Generation, R08.3M05,    Control Totals         1

06/21/2018 std_flat_np2

Name/Address Records Read, File IN             1,531

  Name/Address Records Processed               1,531         100.00 % OF INPUT

Records Marked as Invalid                          2           0.13 % OF PROCESSED
    Records With Invalid ZIP                       2              100.00 % OF INVALID

Records With Valid ZIP Code                    1,529          99.87 % OF PROCESSED

  Nr Records Rejected                              2           0.13 % OF PROCESSED

  Total Records Accepted and Forward           1,529          99.87 % OF PROCESSED

  ZIP+4 Coded Records                          1,529              100.00 % OF FORWARD

  Carrier Coded Records                        1,529              100.00 % OF FORWARD
    Carrier Coded & ZIP+4 Records              1,529              100.00 % OF FORWARD

  Unique Carrier addresses                     1,074               70.24 % OF FORWARD

Name/Address Records Rejected, File OR             2
Name/Address Records Forward, File ON          1,529


Among the information in that section, it includes- 
How many records were read in from the input file "Name/Address Records Read, File IN".
How many records had Invalid and how many had Valid ZIP codes.
How many had Carrier Route information.
How many records (if any) were written to a reject file "Name/Address Records Rejected, File OR".
And how many records were forwarded and will be written to the Name-Address output file "Name/Address Records Forward, File ON".

(The information provided may vary somewhat based on the job setup.)
UPDATED:  March 15, 2019