Hi Kamram,
Sorry for the trouble here with the public attendee list option!
Juts to confirm, do you have the following option selected when creating tickets:

I have that option selected on my test site and that hides the option on the front end of the website (screenshot).
If you do have the option selected and the checkbox is still showing up on the front end of your site, then can you confirm whether it happens when switching to the default WordPress Twenty Sixteen theme? That’s the theme I’m using and it would be interesting to see if that’s the difference.
Thanks!
Geoff