Hi Ronak Shah
Welcome back to the community.
Apologies if you've already checked these resources, but there are some useful articles and help files on dynamic titles available online. For example, the knowledge base article http://kb.tableau.com/articles/HowTo/creating-dynamic-titles-based-on-filters discusses how to change the content of titles using filters (not exactly your issue, I know). The Related links section in that article might also be useful.
A sure-fire way of getting help more quickly is to provide a packaged workbook with your query. There are some great guidelines for doing that posted here.