okay,
i did some reading and, see robots.txt only determines whether Google bots will CRAWL pages/urls for content, it does not guarantee that Google will stop from indexing them.
I have found a solution to stop k2 Items from being INDEXED on Google
In the Backend of your K2 Item -> Meta Data Information -> Robots -> noindex, nofollow
Setting that will set the meta data noindex and nofollow at the <Head> of the k2 Item page that tells robots not to index the Item page url.
