Taboola and Google AdSense are two distinct ad networks with their own approval criteria. That being said, just because you were denied access to Google AdSense does not indicate you will face the same fate with Taboola.
Taboola has its own approval procedure, during which your site or blog is checked for quality, user engagement, traffic, and policy compliance. If your website or blog otherwise satisfies Taboola’s criteria, you may be allowed even if you were not accepted to Google AdSense.
Yet, it’s worth noting that the two services share a common set of rules and regulations for determining what kinds of content can be monetized. Websites and blogs that break the rules on one platform may also be in violation of the rules on another. Hence, to maximise your chances of approval, you should review and abide by the policies of both platforms.