What is the relevance of JSR and how does one optimize it for one's use?
I read something like jsr82 for Bluetooth and some other for other technical apps.
What's its relevance?
JSRs are Java Specification Requests, basically change requests for the Java language, libraries and other components.
It's all part of the Java Community Process, whereby interested parties can put forward their ideas for enhancements and (hopefully) have them taken up and acted upon. The process is detailed here.
For example, the Bluetooth one you mention is tracked here and the definitive list is maintained here.