Hi Pankaj
thanks for your reply. I also made what driven in the jomsocial official description but without success.
Creating the templates/jomsocial/html/com_community/css/ (was not present before) , in the jomsocial backend list of templates I have now 2 jomsocial.
Setting one as default are set as default, but sill not having effect in the frontpage. I put alway an empty style.css to test the overrides.
I also set jomsocial as default in the JS backend and put the style.css in the templates/ireview3/html/com_community/css/ but same effect. I suppose this is the right way to use JS overrides.
Cheers
Adriano