They are everywhere, and mutually interchangeable. Basically, turnarounds are placeholders of harmonic movement. They go a merry round, then back to whatever the tonic or the dominant chord that they replace was, basically.

Here are some quick possibilities for tonic turnarounds:

All the regular reharmonization rules apply, meaning that, in functional terms, Imaj7, I6, iii-7, iii6, vi-7 and vi-6 all fulfill the same role (if I understood well (in principle, and in a major harmonic context).

Body and soul

Cute tune. Listing here a regular form, as collected from different sources:

A section, in Db

II V/II II V I IV7 III IIIbdim (passing)
II (+passing) VII V turnaround I, II-V(in Db)
I, II-V (in D)

B section: centered around D in row 1, then C in 2nd

I II I II/bVII7 bVII7 turnaroundy-thing I(in D)
II V I(in C) IIIbdim II V Chromatic-y part: I7 VII7 V/ii(in Db)

Aaaand back to the A form.