In this paper, we first analyze and classify the empty categories in a Hindi dependency tree-bank and then identify various discovery procedures to automatically detect the existence of these categories in a sentence. For this we make use of lexical knowledge along with the parsed output from a constraint based parser. Through this work we show that it is possible to successfully discover certain types of empty categories while some other types are more difficult to identify. This work leads to the state-of-the-art system for automatic insertion of empty categories in the Hindi sentence.