They best way to know how well you will fare against a T2 boss is to spawn one.
In my experience the T2 crystals are much easier to get than the T1 crystals.
I dont recall how many hps i had on my tank when i first started doing T2 but I know it was less than 100k. I had full T1, RoA 30 and Guardian 15 when i started to tank T2. I had 1 pally and 1 Clr. The CLR i had in my second half full group and single targeted my Tank. It was enough.
The bigger problem was all my other chars had a bigger chance of dying than my tank. A couple of the AEs hit very hard if you dont have the HPs to take them you may lose a few people. Ramps could also hurt a bit starting out.
Something to point out that might catch you off guard - Expect minibosses to spawn from the adds the spawn during the fight. Especially with Kronos.
Since you dont want to waste any Kronos Spawns i will give you another tip to getting the right kronos in case you dont have any pets.
Drop any target you have on one of your DPS characters. On the first AE that character will pick up the correct target.