Q: safari 6.1.6 is not responding

Hi, shyam256. 

Thank you for visiting Apple Support Communities.  

I understand that you are experiencing an issue with the performance of Safari.  I would start with resetting Safari History and clearing Website Data.  If the issue persists, you may need to take a look at the troubleshooting steps in the second article.  

Safari 6/7 (Mavericks): Reset Safari

Unsupported third-party add-ons may cause Safari to unexpectedly quit or have performance issues

Cheers, 

Jason H.