Need help to determine inlet

[Jackooze]

Hey guys, I’ve a new home/pool owner and ran Into a rodent issue that created leaks in several lines. All the plumbing lines have been dug up and I came across one line that was previously cracked and plugged off on the inside of the pool. I am trying to determine was this a return outlet or inlet for vacuum. Its placed in the middle of the pool roughly 4 ft from skimmer. I have two other returns one in the shallow and deep end.

So here is my question should I convert this outlet for return or vacuum?

Pool is 32x16 25,000 gal
Inground vinyl liner.
Pool build in 1980’s
One skimmer
Main drain
Two return outlets
One undetermined.
Po

[Denniswiseman]

How deep in the pool is it

[Jackooze]

It’s at the same height as the other outlet
Midway

[Denniswiseman]

Probably an old return
I would have expected a vacuum port wouldbe higher