|Your post is as clear as mud.|
If you mean the TV has a 15 pin or pin hole VGA port, you can't connect the HDMI output to that.
If you mean the TV has a single RCA video jack, probably yellow, you can't connect HDMI to that, or any of the three HD TV (composite) RCA jacks to that.
If you mean the TV has 3 RCA jacks for HD TV (composite) , you can't connect that to HDMI.
You can't make the TV display in HDMI mode or HD TV (composite) video mode if it isn't capable of that.
You may be able to connect to the TV another way - that varies from card to card.
Which make and model of card is it?
Do you have jacks or ports on the TV other than "rgb"