OK, I put this here because it happened to me as well and it was the first time it did. This is how to be in whatever team you want in TDM. OK, this is how you do it, and it worked with me.
The first time you arrive you are put into Blue. You want to be in Red. So you leave the server and join again. Then you are still put into Blue. And you keep leaving and leaving and leaving and no matter how much you do it, your'e always put into BLUE. So this is what you do, and this is when I get crazy, but clever. Join the server, then on the loading screen (usally works with datablock load), say, and exactly how I say it, "Dear God, please put me in (team)." You don't need to use "'s but you will need to use punctuation. Do not use any word shorts like u, plz, and all that. And after I said it, I was put into Red O_O
That's one thing you can try. It won't always work, but it's worth trying. It sounds crazy, but it worked for me. And God can change luck and unluck.