Manoj,
To create tests that simulate user actions on your application, you need to know the object hierarchy of your application and the methods and properties the objects contain. So, you need to have an application to do this.
Without the application you can, perhaps, create only test scripts (not keyword tests) that implement a general infrastructure or framework. Creating scripts simulating user actions in these conditions is error-prone. Most likely, after you get the build, you will have to fix errors in the script code written "blindly".
If you have a previous build of your app, you can start creating tests on it and then update your tests after you get the appropriate build.
