http://vsnobs.com/topic/35-raid-boss-stats/

Boss' DEF less than 10k caps at DEF+10k = ATT Cap (Iset 18k)
Boss' DEF greater than 10k caps at DEF*2 = ATT Cap (Kraken 28k, Lakoria 22k)

Example:
Havan has 11K DEF. Add 10K to that. 11K * 2= 22K. Therefore, Havan's ATT cap is 22K ATT.

Crit cap is boss crit resist + 50.

Example:
Lakoria has a Crit Resist of 59. 59 + 50=109. Therefore, the Crit cap is 109 for Lakoria.

Just a side note: 140 seems to be the highest, so it is the Crit cap currently. 114 if we want to just focus on other raids but Liono.