If I toiveled a pot with a label Attached to the back outside part is it ok or pot needs to be clean inside out?

Shalom, Thank you for your question. When dipping a pot in a mikvah in order to toivel it, one needs to make sure that there are no intervening substances between the pot and the water (chatzizah in hebrew). For example, dirt, glue, or, in your case, a label. If the label was stuck on to the pot, even on the outside, it invalidates the immersion. This is assuming that we are talking about the type of label generally removed from pots, such as a price tag etc, and not those which are often left stuck on, such as on the underside of the vessel where there is sometimes the manufacturer’s designer label. If the label was of the type normally removed, then you need to clean the pot, and re-immerse it. Blessings.