According to the data sheet, the Delta 3200 should be developed for 12–14 minutes in the stock solution, with 12 minutes for condenser enlargers and 14 minutes for mixed-light enlargers.
To be on the safe side, I’d start with 12 minutes; if the film turns out too soft, you can always compensate slightly by using a harder gradient during enlargement.
But not at 3200 ASA, rather at around 1000 ASA. I’ve extrapolated my times from the data in the datasheet on a 1+1 basis and added a little extra, so that I’m working with mixed light at a grade of 2.5 to 3.
Regards, Sven.