Q1, INFA licenses: as far as I know licenses are CPU core based. It is your own responsibility to make sure that you don't use more CPU cores in your environments than you are licensed for.
Q2, DR not working: what do you mean by saying that licenses are only held on PROD side? Could you please explain a bit more accurately what you mean to say here?
Thank you Nico Heinze.
Basically, I wanted to understand how the licenses work on ACTIVE-PASSIVE environments so that one service runs at a time – To be more precise, If we switch over the licenses from production to DR environment which has the similar specs as production, we need to know if DR service run without any issues?
Yes, that will run.
Beware that an active-passive combination bears some potential trouble. There have been quite a few discussions about this topic and related things in the past years, you might want to browse the archives for more details and other discussions on this. It will take some time, but on the other hand you will get a good overview of what has to be taken care of, what pitfalls will arise with which strategy, and so on. This is a HUGE area of discussion.