Step 1: Use VSEPR.
A T shape comes from three bond pairs and two lone pairs, written AX$_3$E$_2$.
Step 2: Check the species.
PCl$_3$, SOCl$_2$ and [IO$_3$]$^-$ each have one lone pair and are pyramidal. BrF$_3$ has two lone pairs in a trigonal bipyramid.
Step 3: Pick the T shape.
Only BrF$_3$ fits AX$_3$E$_2$ and is T shaped.
Step 4: Answer.
\[ \boxed{\text{BrF}_3} \]