I have a series of photos 3840x2880 which I want to crop to make a 1080 timelapse video to be uploaded to YouTube.
Which sequence setting in Adobe Premiere CS6 I should use for YouTube videos?
There are presets for Youtube specifically already in Adobe Media Encoder. I would suggest using one of them. You can also find the technical recommendations from Youtube on how to encode the videos here, however I believe the presets already conform to these recommendations.