I assume this question is nothing to do with using the SKILL programming language to customize the Cadence Custom IC tools, but more a question on how to design a clap switch as a university project?
A simple google search for "clap switch" seems to give plenty of resources and circuits. I assume your question is which IC (i.e. which specific integrated circuit) you should use; I would do some research using google first. Even then this is unlikely to be a relevant forum for you because this is for customizing the Cadence tools; even the sister forum "Custom IC Design" is unlikely to help unless you're actually designing the IC itself.
Of course, if I've misunderstood your question, you may just need to clarify what it is you're after.