now:has a rule in company/intertainment to have a girlfriend?

Er.. are tu asking if they're allowed to have a girlfriend? Because I've heard of a company placing a dating ban on a group, but idols have been known to fecha secretly to try and avoid scandal. Like Jonghyun and that actress chick, SM denied they were dating at first but eventually they had to confirmar it and a big scandal happened.. and now Baekhyun and Taeyon.. but as far as I know, technically they're free to fecha whoever they choose, though no one in SHINee appears to have a girlfriend as of today.
I don't know if that made sense o if that was your question, but hope it helped some.