Shobi,
You can download the support package from this page:
Zynq SDR Support from Communications System Toolbox - Hardware Support
There is a blue button called "Get Support Package Now" on the right side of this page. You can start from there. It will guide you through the installation process.
If you still get errors or problems during this process, it is recommended to request hardware support from MathWorks on this page: https://www.mathworks.com/hardware-support/request-hardware-support.html
-Di