Originally Posted by usman khalid

I think you should not waste much time on this especially when little time is left in exam. Because there may be different synonyms/antonyms for a particular word and the book you study might not have listed that word. However, you may cosult GRE book for this. It contains a list of 750 Synonyms/Antonyms mixed. Actually, at the end of every vocab section, there is a list of 15 words along with their synonyms/antonyms and there are total 50 sections.