This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
Let me guess what your exact requirement is. You have listview that displays the data in tamil font, right? You have an edittext where the user a text and that is in tamil, and the searched result is displayed in text view, right?
Instead of implementing your own search solution, I think it's much better to hook into Android's built-in search framework. If you organize your content as a ContentProvider, and declare it to be searchable in the manifest, then you can use the system-wide search box to search for your content.