Tv set up

I don't know where to plug the coax cable for my tv into. I already had internet and when that was first installed the installer had to drill a hole into the floor and feed a cable up to the connect the internet modem to because there is no wall outlet in the 1960 built house. I am assuming  that wire is a coax cable port. But where do I plug the coax cable into if the internet is already plugged in.