Hi Rahul,
The ‘scenario’ is the TestRun. The TestRun contains the manoeuver and traffic parameters.
If you open the Python API documentation and click on Getting Started then you will find a section dedicated to ‘Parameterizing variations’. In this section there are a number of examples of varying scenario parameter key values. You would just need to open your own TestRun to find the exact key you would like to vary and then adapt the example accordingly.
The Python API documentation can be opened from the main CarMaker GUI under Help > Additional Documents > CarMaker Python API Reference.
If you have any problems then feel free to post the code you have developed so far and the exact key/s you are trying to vary and we can probably help further.
David