I downloaded a 5GB torrent file using tixati software, and when it completed the downloading (100%) it started seeding (idk what that means) anyways it has been "seeding" for 2hrs and a half now, reminder that the file is only 5GB in size, so is it normal to take this long or is the app not functioning properly or is there a problem with the file. Please help and Thanks!

If the torrent was seeding it is complete.
Seeding usually = complete.

Seeding = Sharing is Caring.

Seeding a torrent means you've finished downloading all the files you selected (or the entire torrent if you didn't select any files) and are now exclusively sharing with others instead of downloading anything (for that torrent). Just like you downloaded the files from other 'peers' (those with <100% files) and 'seeds' (those with 100% files) in the 'swarm', seeding means you're now continuing to share with others whatever you've downloaded.

You can at some point when you feel you've shared enough (ideally at least 1:1) stop the torrent and delete its entry from Tixati (don't delete the files themselves by mistake though!). After this you can move the files around, rename them etc. without causing any issues while seeding.