How to Install CometChat. Help needed

Hello experts. I have downloaded cometchat nulled and tried installing. but it gives me error while installing on server. * Please check if CometChat is installed in the correct directory. The 'cometchat' folder should be placed at /cometchat)
Can anybody help me sort it out? I followed all instruction installing. changed directory permissions update database values in integration file but everything failed.
Any IDea or if anyone has the solution.

Regards