what if you enter a under 1199 tournament then before the event have a higher rating

I dont know because you could go back and forth so you could enter toneys

I am pretty sure that Chess.com automatically checks ratings when tournaments start and drops those players whose ratings at that moment don't qualify.

However, some tournaments announce that they will enforce restrictions for subsequent rounds and those have to be done manually by the tournament director.

What if your rating is above 1199 after you enter the tournament and gain the extra ratings because of matches in the tournament.

What matters is your rating when the tournament actually starts.

No that is not what I mean, your rating is under 1199 rating and the tournament has already started, and then your rating gets above 1199 in the tournament after it has started. 

So, you are in the tournament and it has started and you have a rating of less than 1199.
Then you play matches in the tournament and your rating goes above 1199.
What happens then?

You stay in.

Ok

I know that now