Ant not Running (test ng folder in init is highlighted)

<taskdef name="testng" classpath="${test.classpath}"
classname="org.testng.TestNGAntTask" />
code showing warning in build.xml file and following warning comed on hovering move over it:

taskdef class org.testng.TestNGAntTask cannot be found using the classloader AntClassLoader[C:\Users
\ra321432\Desktop\automation\jars\access-bridge.jar;C:\Users\ra321432\Desktop\automation\jars\cglib-
nodep-3.2.4.jar;C:\Users\ra321432\Desktop\automation\jars\charsets.jar;C:\Users\ra321432\Desktop\automation
\jars\cldrdata.jar;C:\Users\ra321432\Desktop\automation\jars\client-combined-3.0.0-beta2-nodeps.jar;C:\Users
\ra321432\Desktop\automation\jars\commons-codec-1.10 (2).jar;C:\Users\ra321432\Desktop\automation\jars
\commons-codec-1.10.jar;C:\Users\ra321432\Desktop\automation\jars\commons-exec-1.3.jar;C:\Users
\ra321432\Desktop\automation\jars\commons-logging-1.2.jar;C:\Users\ra321432\Desktop\automation\jars
\deploy.jar;C:\Users\ra321432\Desktop\automation\jars\dnsns.jar;C:\Users\ra321432\Desktop\automation\jars
\gson-2.3.1.jar;C:\Users\ra321432\Desktop\automation\jars\guava-19.0.jar;C:\Users\ra321432\Desktop
\automation\jars\hamcrest-core-1.3.jar;C:\Users\ra321432\Desktop\automation\jars\hamcrest-library-1.3.jar;C:
\Users\ra321432\Desktop\automation\jars\httpclient-4.5.2.jar;C:\Users\ra321432\Desktop\automation\jars
\httpcore-4.4.4.jar;C:\Users\ra321432\Desktop\automation\jars\httpmime-4.5.2.jar;C:\Users\ra321432\Desktop
\automation\jars\jaccess.jar;C:\Users\ra321432\Desktop\automation\jars\javaws.jar;C:\Users\ra321432\Desktop
\automation\jars\jce.jar;C:\Users\ra321432\Desktop\automation\jars\jfr.jar;C:\Users\ra321432\Desktop
\automation\jars\jfxrt.jar;C:\Users\ra321432\Desktop\automation\jars\jfxswt.jar;C:\Users\ra321432\Desktop
\automation\jars\jna-4.1.0.jar;C:\Users\ra321432\Desktop\automation\jars\jna-platform-4.1.0.jar;C:\Users
\ra321432\Desktop\automation\jars\jsse.jar;C:\Users\ra321432\Desktop\automation\jars\junit-4.12.jar;C:\Users
\ra321432\Desktop\automation\jars\localedata.jar;C:\Users\ra321432\Desktop\automation\jars
\log4j-1.2.17.jar;C:\Users\ra321432\Desktop\automation\jars\management-agent.jar;C:\Users\ra321432\Desktop
\automation\jars\nashorn.jar;C:\Users\ra321432\Desktop\automation\jars\netty-3.5.7.Final.jar;C:\Users
\ra321432\Desktop\automation\jars\phantomjsdriver-1.2.1.jar;C:\Users\ra321432\Desktop\automation\jars
\plugin.jar;C:\Users\ra321432\Desktop\automation\jars\poi-3.14-20160307.jar;C:\Users\ra321432\Desktop
\automation\jars\poi-examples-3.14-20160307.jar;C:\Users\ra321432\Desktop\automation\jars\poi-
excelant-3.14-20160307.jar;C:\Users\ra321432\Desktop\automation\jars\poi-ooxml-3.14-20160307.jar;C:\Users
\ra321432\Desktop\automation\jars\poi-ooxml-schemas-3.14-20160307.jar;C:\Users\ra321432\Desktop
\automation\jars\poi-scratchpad-3.14-20160307.jar;C:\Users\ra321432\Desktop\automation\jars\resources.jar;C:
\Users\ra321432\Desktop\automation\jars\rt.jar;C:\Users\ra321432\Desktop\automation\jars\sunec.jar;C:\Users
\ra321432\Desktop\automation\jars\sunjce_provider.jar;C:\Users\ra321432\Desktop\automation\jars
\sunmscapi.jar;C:\Users\ra321432\Desktop\automation\jars\sunpkcs11.jar;C:\Users\ra321432\Desktop
\automation\jars\zipfs.jar]