Hi
I wonder where did you find this command line!
As svn is a command line command you should follow strictly the parameter so you should have --username instead of --nombre de usario
Keep in mind that --nombre de usario, due to the spaces is consider as an addition of option --nombre followed by option "de" and "usario". none of these options exists!
As you plan to install telemac, you should install the latest version and then change v7p2r2 by v8p1r2
Finally, you couldn't have spaces in the destination directory!
The command you should enter is:
svn co
http://svn.opentelemac/org/svn/opentelemac/tags/v8p1r2 C:\opentelemac-mascaret\v8p1 --username ot-svn-public --password telemac1*
regards