So basically I'm trying to cast live footage of webcam connected to PI to my website. I can do that easily with iframe and IP address of PI, but the problem is it will be watched by at least 40 peoples at a same time and this will lead to a huge load on PI and I think It can't handle that much load. So is there anyway that the all of the load will be putted on the website instead of PI. Hence consuming less bandwidth of PI to website connection.
try using a livestream host. I found this site here the first option looks like what you need. im not sure if this takes the load off your pi, but you might as well give it a try.