Try the below:
1. If the VO dont have rowimpl.java, then extend the VO and make rowImpl.java
2. Make the rendered property to PPR syntax for the new button column in personalization
3. Extend the page CO and in PR, take the table control using proper bean and use PPR and from the extended VO get the values and check if salary >12k..set rendered for the button to true else false.
check your vo.getAttribute("Salary") at row level in loop and refer below link for enable and disable Dept Address Details button on condition.
Let me know for any issue.