So if you don’t romance Tali in ME2/3, Garrus ends up with her.
If you’re female shepard and don’t romance Garrus, Tali and Garrus end up together still.
If you’re male shepard and DO romance Tali, Garrus does not end up with anyone.
Following this chain here, without the introduction of female shepard, Garrus does harbor feelings for Tali no matter what. However he puts that/any ill feelings he may harbor to male shepard aside easily and is still your space cop buddy.
Garrus confirmed the best space bro.