I cannot simply shove as its pot limit and elected instead to raise pot call it off being the shortest stack in the tournament. 

i elect to raise pot and the BTN 3bets enough to put me in. He is very straightforward and i'm likely seeing a range of TT+ AQ+ maybe AJs 99 etc the LIVE tells he gave off suggested to me he was strong but i didn't know much more than this. 

If i choose a different sizing eg minraise, am i allowed to fold given ICM calculations? i can see how this might be different if i'm one of the medium stacks but if i'm the shortest stack in the field?

The average stack was 12-15bb, everyone was quite close together.

i'm calling 5bb to win 8.5bb 5/13.5= 37% but what about ICM considerations?