Please use the following links to download the specification.

OSGi Core Release 6 Specification
OSGi Core Release 6 Companion Code
OSGi Core Release 6 Annotation Code

OSGi Compendium Release 6 Specification 
OSGi Compendium Release 6 Companion Code 
OSGi Enterprise Release 6 Specification 
OSGi Enterprise Release 6 Companion Code

OSGi Residential Release 6 Supplement 1 Specification
OSGi Residential Release 6 Specification 
OSGi Residential Release 6 Companion Code