Is it normal to have a tissue type thing coming out of rectum after a colonoscopy

That is not normal. Depending on what was done this could be pieces of polyp tissue that were incompletely removed or retained stool from the prep. You should call the endoscopist who performed the procedure to discuss this with them.

If a polyp was removed or biopsies were taken, a small amount of blood (few drops) is not uncommon, however actual tissue is not normal and your doctor should be notified. Protruding tissue may be a prolapsing hemorrhoid or rectum but should be evaluated.

It is unclear what that would be. I would call your gastroenterologist to discuss.