I'm not sure if you can set the active take at playback time, but I'm sure you can script it.
Here's a draft on how to set a random take for all selected items:
* Get the number of selected media items
* Iterate of them and do the following for each
- * Get the number of takes
- * Pick a suitable random numer
- * Set the take with the chosen number as active
Masi
https://www.reaper.fm/sdk/reascript/...ctedMediaItems
https://www.reaper.fm/sdk/reascript/...ectedMediaItem
https://www.reaper.fm/sdk/reascript/...tml#CountTakes
https://www.reaper.fm/sdk/reascript/...l#GetMediaItem
https://www.reaper.fm/sdk/reascript/...iaItemSelected