Q: Iphone hosts files

No.

Why do you need that feature?

You could use an app like "Weblock - AdBlock for iOS" to block certain sites, if that's what you're after.

You could also look at an MDM/Profile Management solution.

With a normal user installed iOS, there is no access to system files at all.

If you explain your aim we may be able to suggest alternatives, such as setting up your own wifi router with custom DNS entries to redirect to local network addresses.

You could also use a custom DNS server on the internet too if you need to redirect for whatever reason but you are giving us so little info that it makes it impossible to know what may help & what will fail.