can i put removed games on giveaway?

:O Much removed, very gibz. WOW! :3

Don't make GAs using a different/wrong name. That is against the rules and will lead to a suspension.

i have a bunch of them.

Yes.

edit :am i allowed to put them on giveaway under a different name and put the actually name of the game in the description?

No.

From the SG guidelines:

Giveaways should accurately reflect the game being given away. If the game is not available in the giveaway list, please contact support to have the game added, instead of posting the giveaway under an incorrect name.

https://www.steamgifts.com/about/guidelines

Side-note, you can view the basises for, and durations of suspensions at the bottom of this page.
Bit easier to work through than the site's FAQ, though you should definitely look through that if you get the chance, as well.