I have entered the 7th Chess.com Tournament 1201-1400. When I registered, my rating was 1210, but now it is below 1201. I am still registered for the tournament, so how do I delete my name from the registrant list?

You can if you wish but read the "Note" below the list of recently registered players.

To withdraw from member-created tournaments see the Help link on the right side of any tournament page. There is an entry for "How do I withdraw from a tournament". Ignore the part that says "withdrawing from a tournament while you have games in progress will automatically cause you to forfeit all your games on time and negatively affects your timeout % ratio.". Timeout ratio is unaffected.

 Are you sure about that?

I believe that at the start of the tournament, an automatic check is done and you will be put in the appropriate bracket for your rating.

Sure about what?

Assuming you are concerned about the penalty for withdrawing from tournament games in progress.  See here where a player was disappointed by NOT getting timeouts.

 That is right. You don't have to withdraw at all. You will automatically be put in the correct bracket when the tournaments start.

Okay. Thank you everyone