Hi am java developer with decade of experience with java/j2ee development, I got a chance from my organisation to do course and certification in bluemix or softlayer , and am confused what to choose. Any suggestions guys
This is really up to what you want to do and what you are comfortable with. SoftLayer is an Infrastructure as a Service Provider. This means that you as the customer are responsible for the Operating System updates and configuration, Middleware, and applications and services that you want to use.
If you would rather focus on just the code and don't really need to tweak the underlying OS or software stack than I would say Bluemix is the way to go as it is really more focused on Developers.
Really though it comes down to what you ultimately want to do with the platforms.