HimanshuP:

You'll need the Sybase client libraries on the machine, and the SYBASE environment variable needs to specify the path to them so that the DBD::Sybase package can be built and linked. The DBD::Sybase documentation gives the path '/usr/local/sybase' as an example location. If you're installing on a machine that doesn't have the Sybase libraries on it, then you can download them (when I last checked, a few years ago) from the Sybase site.

I just checked, and it appears that you choose Products --> Adaptive Server Enterprise --> Evaluate --> Downloads --> ASE Developer's Edition. Then you'll get to the "Register and Download Now" button. (I didn't go further.)

...roboticus