I want to port few C/C++ libraries to Android, how feasible it would be
e.g. OpenSSL can it be ported or suppose an application which depends on OpenSSL, what is the bes
The android internals wiki is a good starting point, and includes a link explaining how to compile simple native applications.
Scratchbox does seem to be the way to go for compiling more complex apps & libraries, as you probably know already. I would suggest contacting those folks to get a bearing on your OpenSSL project.