How to execute test cases written in Devtest 9.5.1 from Jenkins? If yes, what are the syntaxes being used? How to call individual test case or entire test suite?, etc
Yes.
One way is to create an Ant script that uses curl or some other REST application and invoke the test case using DevTests REST API. Example:
http://<dterver>:1505/lisa-invoke/runTest?testCasePath=/dir/test.tst&stagingDocPath=/dir/test.stg&
See:
Run Test Suites with LISA Invoke - DevTest Solutions - 10.0 - CA Technologies Documentation
Run Test Cases with LISA Invoke - DevTest Solutions - 10.0 - CA Technologies Documentation