HELP! I don't understand why it says T3 level, not T4 of 96 mana.

Your mana affix is level 54, crit is level 41. It's not based on tiers.

it’s not based on tier it’s based on level of the mod becomes rollable. check craftofexile

The modifier tier does not correspond to the item level of the modifier. As an example, T1 mods can be as low as say 40 and as high as 82.

Because it targets the tier of the mod not the T of the mod.

Sound crazy? Of course it does.

https://poe2db.tw/us/Wands#ModifiersCalc

Look on this page and find the green bubbles called tier to understand. It's not the T on your wand, it's the tier on the mod. Confusing AF.

While this item is active in your inventory your next Chaos Orb will remove the lowest level modifier. No mention of tiers. Your crit affix is level 41, while your mana is like 59

It's targeting T3 Crit instead of T4 mana? That's fukked up, bro. But yes, GGG needs to make several sweeping changes to ilvl weapon modifiers.
Life/Mana per kill, and mana regeneration (suffixes) in particular.
I have advocated removing the removing pure mana from the pool entirely.
But what you CAN do to remove that mana is simply use the recombination. Find a wand with like t10 mana and recombine it with that wand and an omen of recombination. It should be 75% chance successful or something. Then, whittle the very low level mana.