Hello Thangavel Ayyasamy,
Since version 7.0 Thingworx allows to customize location of your Thingworx Repositories. All you need to do, is to create a folder named ThingworxPlatform in the root of your Tomcat/Thingworx installation (e.g. if your Tomcat is installed in C:\Program Files\..., you should create a folder: C:\ThingworxPlatform and so on).
There you should create a file named platform-settings.json. Inside you can put a various configurations for your Thingworx Platform, also for the File Repository root location. The configuration should be in JSON format. The minimal necessary configuration for your task would be:
For another possible configurations and the general information, please refer to the Help Center: Digital Media Publisher and Thingworx Installation guilde.
Please note, that all necessary read/write permissions needs to be granted to the location specified. Otherwise your Thingworx won't startup properly.
Hope it helps, don't hesitate to ask for further assistance.