Hi Ganesh,
As suggested by Mr. Kiran, you can enhance the leave application and add the functionlity of attachments.
Please refer the below document.
 | Attach files with save, retrieve and delete functionality in Web Dynpro ABAP - Part 1 |
The above document clearly explains about how to bring in the attachments with save, retrieve & delete functionality.
Hope this helps you.
Regards,
Rama