That's rather difficult to answer - the second letter is the "famous" czech "Ř" 8) The word has two syllables Břec-lav or Bře - clav, both possible e as e in ten lav contains "open a", pronounce as "love" or better "laugh" c as ts or tz together: brshets-love if you say brets-love, anybody should understand I am not sure, if this helps, you may try a web page with pronounced Czech, there are several links even here in some discussions.
http://www.speechtech.cz/demo.php copy and paste this word: Břeclav into the box and then click on Syntetizovat. It will say it for you.