Okay I really really need this info asap. How many bank slots and personal inventory slots are available at each tier?

i believe a whole row is added

Correct. I think its 6 for inventory and 12 for bank, or something like that. However long a row is.

So at lt how many slots do you have?

inventory is around 36 i think
bank is probably the same

though it really doesn't matter because you rank up pretty quickly and you rarely run out of space, unless you are an item hog :p

EDIT: Just checked in game. If I'm doing the math right then you start off with 36 inventory and bank slots. Each rank up gives you 6 more inventory slots and 12 more bank slots.