If you choose IR, things will be very easy for you. I got 110 with hardly 3 days study, but another friend studied few days more and he got 90 only.
If you get IR, then u will need to prepare for IR + Phy + any 2 subjects of choice. Really less headache. I also have IR + Phy combination.

Public ad is safe choice, i studied it last day and got 66.

Either take IR, or if you are confident with rest of the subject selection, choose public ad and give it a week.