Hi Anandkumar
yet another maverick style requirement from you ;-) 
For sending to the same user -> SWIA --> Replace Work item -> this will redetermin the Agents and set it to Ready Status.
However, you said:
"work item is also not showing any Agents Option. Only Possible Agents and Excluded Agents option is there"
Does this happen when the WI gets created or someone plays around with it? Normally, if the WI gets created and we do not have any agents button (only Possible and excluded Buttons), this means that the Agent determination did not result in any actual agent and the WI has gone to ALL Possible Agents (in older releases). In new Releases, it just sits there, tapping it's fingers for Admins like you to pick the poor guy and send it to a user :-)
You can cross check this by looking for the WI in SWI2_ADM1 (Work items without agents).
If that's the case, first analyze why the Agents were not determined, then fix that and finally replace the WI (or Forward the WI).
Regards,
Modak