I looked at that same truck hard for a smaller 5th wheel and decided no.
A handful of the 2500's have good capability but most of the Rams are very low on payload capacity, and a 12000 empty will be a 13500 at best loaded unit meaning your pin weight will be north of 3200 lbs, add for the hitch another 200, and then any others travelling with you and most Rams are overloaded.
Tow cap will show as ok,
Payload will probably not.
Some may say different, and to actually pull it you will have plenty of power, but your suspension and frame will be technically overloaded in most cases. Check your door pillar sticker and you should be able to find your numbers, your old window sticker if you saved it should tell you as well.