T.I. -- His Welcome Home Party Is ... A Brunch?

T.I. is re-writing the book when it comes to welcome home parties -- because the recently-released rapper isn't throwing himself a nightclub bash ... he's having a brunch in Atlanta!

But don't expect tea and crumpets -- we're told good pal Diddy is personally shipping in 150 bottles of Ciroc, one for each person in attendance. We're told the whole bash will cost around $100K, with $20K just on food and additional $8K on dessert.

The big surprise of the night -- reps from AKOO Clothing, T.I.'s clothing line, will measure the VIP guests for custom-made clothing gifts.