Hi Saransurendran,
A common cause of the issue you describe is that not all files from the WAAS SRE ZIP archive are available in the same folder on your FTP server, or permissions are not good for all files.
There should be 6 files on your FTP server in total, all in the same folder:
•waas-accelerator-4.4.3c.9-k9.bin
•waas-accelerator-4.4.3c.9-k9.bin.install.sre
•waas-accelerator-4.4.3c.9-k9.bin.install.sre.header
•waas-accelerator-4.4.3c.9-k9.bin.installer
•waas-accelerator-4.4.3c.9-k9.bin.key
•waas-accelerator-4.4.3c.9-k9.bin.srebootloader
If any of these files should be missing or not accessible on the FTP server, installation will fail.
Please ensure you have all these files available and accessible on your FTP server and retry.
Please also check the following documents for further information on installing WAAS on SRE:
http://www.cisco.com/c/en/us/td/docs/app_ntwk_services/waas/waas/v421/module/installation/guide/wssmcfg.html
https://supportforums.cisco.com/document/85376/deploying-waas-isr-g2-sre-module
Regards,
Michael