By spending some more time reading blogs:

I found solution as below:

downloaded java-json.jar file from location http://www.java2s.com/Code/Jar/j/Downloadjavajsonjar.htm

stored this jar file at location /usr/lib/sqoop/lib/java-json.jar

But I wonder, if JSONObject class is required to process sqoop import, why it is not found in any json jar found under hadoop classpath or anyother component classpath?

when searched for available json jar files I found below list

./usr/lib/hadoop/lib/jersey-json-1.9.jar
./usr/lib/hadoop-yarn/lib/jersey-json-1.9.jar
./usr/lib/hadoop-mapreduce/jersey-json-1.9.jar
./usr/lib/hadoop-0.20-mapreduce/lib/jersey-json-1.9.jar
./usr/lib/hive/lib/metrics-json-3.0.2.jar
./usr/lib/sentry/lib/jersey-json-1.9.jar
./usr/lib/sentry/lib/metrics-json-3.0.2.jar
./usr/lib/kite/lib/kite-morphlines-json-1.0.0-cdh5.10.0.jar
./usr/lib/kite/lib/metrics-json-3.0.2.jar

Any expert advise appreciated.

Thank you!