The rest apis for Sonarqube 6.0 version is:-
1.(SonarqubeUrl)/api/issues/search=>For Technical Debt.
2.(SonarqubeUrl)/api/resources?metrics=ncloc,coverage=>For Code Coverage.
3.(SonarqubeUrl)/api/resources?metrics=ncloc,test_success_density=>For Unit Test Success.
4.(SonarqubeUrl)//api/resources?metrics=ncloc,test_failure_density=>For Unit Test Failure. Sources.
a.https://docs.sonarqube.org/pages/viewpage.action?pageId=2752802
b.https://docs.sonarqube.org/pages/viewpage.action?pageId=2392181