foreach line [split $content \n] {
if {[regexp -nocase {<a\shref="\/genre\/(.*)">(.*)<\/a>} $line match genre1 genre2 genre3]} {
and i knwo, that is bad. Next problem: Im not knowing at the beginning how many genres ill have to parse. it can be just one or up to 4 or somethg like that.
Could you post the link to the website? Might be easier to see how it handles different kinds of input and how it changes the code.
foreach is a good start btw, but why don't you add each match to the end of a single variable like set real_var "$real_var|$match" - this way you don't need to make the regex match do all the work and you get a near unlimited amount of genres you could add so long as they match the regex. They'll all end up looking like Adventure|Action|Fantasy with the above example.
