Premiere Pro - Change indeterminate Media Time-base to custom value (say 12 fps) Is it possible to change the indeterminate time-base in Adobe Primeiere Pro to something small like 12 fps (the figure below shows only a few pre-fixed values) ?

If not, how do I render a 5 second video with 60 images at 12 fps ? I do NOT want to use time-remapping as an effect since I am worried that will try to interpolate frame, whereas I have 60 frames, which is required for 5 second at 12 fps.

Any help would be appreciated.
When you create a new project, on the 'Settings' page, select 'Custom' from the 'Editing Mode' drop-down, then you can select '12fps' as the 'Intermediate Media Timebase'.

If you already have a project, you can create a new sequence and select 'Custom' and '12fps' as above in the 'Sequence Settings' menu.