I have to set 'sysproperty key="org.uncommons.reportng.escape-output" value="false"/' in TestNG.
Thanks in Advance.
The fist part of question could be addressed by accessing following menu - Run -> Run|Debug Configuration -> Your Configuration -> 'Arguments' tab -> VM arguments. Add following line to the text area:
-Dorg.uncommons.reportng.escape-output=false
For the second question, refer to TestNG Ant documentation:
<testng>
<sysproperty key="org.uncommons.reportng.escape-output" value="false"/>
<!-- the rest of your target -->
</testng>