Hi Amit,
You can invoke any specific test method by specifying that method name in your testng file, but remember your before and after methods will execute in addition to your test method.
<suite name="test" verbose="1">
<test name="CallMethod">
<classes>
<class name="yourclass" />
<methods>
<include name="GenerateReport"></include>
</methods>
</classes>
</test>
</suite>
Here it invokes,
initializeWebDriver() - default
getURL() - default
GenerateReport() - Your method
Do let me know if it didnt help.
Thanks,
Uday