When you say "apply for tier 2 visa", I assume you mean Skilled Worker visa? This recently replaced the Tier 2 (General) work visa. Or have I misunderstood what type of visa you're referring to?
The presence of the Cifas marker itself will not impact the visa application. The Cifas marker is not recorded in the PNC (Police National Computer) database, nor does its presence form part of DBS (Disclosure and Barring Service) search.
Given that a type 6 Cifas marker refers to "First Party Fraud", it's possible that a criminal prosecution took place. Did it? If so, then that could affect the visa application. Otherwise, you're fine.