There are various third parties and business partners that provide this integration capability. As a start, I'll direct you to a business partner that offers this integration:
http://www.cm-logic.com/
(ref: http://www-01.ibm.com/software/rational/announce/quality/partners/ )

Hi,

Yes, at CM-Logic we have developed the JIRA integration to RQM/RTC, it is called JazzConnect-JIRA. Find out more at: http://cm-logic.com/software/cm-logic/jazzconnect-jira.html

Over 50% of our customers are using the integration with RQM.

Please contact me if you need any further information.

Thank you
Stephen Toop
CM-Logic Ltd

Can Atik - did you find an answer to your question?  I have the same question.  Nothing I find offered here replaces RTC.  Only offering I see is to sync the defects from RTC to JIRA or other tools.

all of the tools that create documentation of failed execution (defects) do it in their own database

Jira
HP/QC
RQM
...
if your practitioners who SOLVE these problems don't use those tools, then you have to find some way to join that system with theirs.  OSLC says you can create shadow objects and LINK to the originals, and get 'most' of the function of the source system.

after working on defect mgmt and process for a long time, I don't think this really works.

new development
developer sets done (unit tests work)
   build works,
   test fails, create defect.
what is the defect in the source system?
   developer is NOT done.. reopen prior task.
                                                create NEW defect?
   was there a code review, if so IT failed too.
   etc, etc..

work on new defect,
    developer sets done (unit tests work)
     build works
     test fails ..... what to do..

linking is NOT enough

 Hi  Stephen Toop  The Jazzconnect-jira is fine with RTC how about RQM i didn't find any documentation for RQM synchronization with JIRA  could you please help on this how I can configure JAZZ-coonect jira with RQM and JIRA