In principle you are right. The following script will extract everything between a "<tr>" and "</tr>" tag. It will assume that there are no multiple "<tr>-</tr>"-pairs on a single line and the tags themselves are all lowercase (no "<TR>").
The result might not be what you need, though, so you might consider giving us a sample of what you have and what you will need to get from it. This would help us to help you better.
Code:
sed 's/.*<tr>//;s/<\/tr>.*//' /path/to/your/file
I hope this helps.
bakunin
