We built a new house and there is a cable jack in every room. The house was wired for satellite tv. We have 6 tv's but we are only getting a 4 room system so I'm wondering if we can use those cable jacks to watch tv in other rooms without receivers.

yes, if the cable and ends are good. You will have to watch the same channel on 2 tv's. I suggest you use the TV2 side of each receiver as then you can bring the remote and be able to change channels.