Q: i have inserted the sim ,,.but isnt working properly..signal getting go nd come,,.plz fast reply,,

Hi, Mihir makhani.  

Thank you for visiting Apple Support Communities.  

It sounds like you are receiving a no service message when you inserted a new SIM card.  Here is a troubleshooting article that I would recommend going through for this issue.  

If you can‘t connect to a cellular network or cellular data

Cheers