Hi Hector,
You mean *.rpt file (Crystal report file extension)?
If yes then go to Administrator-->Setup-->General-->Report & layout manager. Report and layout manager screen will open. On Left hand side you'll see a list tab where you"ll get all module of SAP b1. Now select the Module where you want import your Report or layout and click on Import button on Right hand side in report and layout manager. Once you click on import "Report and layout import wizard open"
Step 1: choose your *.rpt file form browse option. After that choose option "Content type". Layout or Report and click on browse option as given below...
If you select Layout option and click on Browse option then "List of Document type" will open you have to choose from where you want put your layout.
If You select Report Option and click on browse button then "Menu selection form" will open and you have select report section where you want to put your *.rpt.
I think it may help you...