Since Russell originally is French for "Redhead" - рыжый - there is no equivalent in Russian or the other Slav languages, which have a very different tradition for personal names. Yet, it could be a surname, like Czech Červený, also common in Slovak - and from there in Hungarian: Cserveny. Ukrainians also have their Червоненко. Russian Краснов Originally in Russian красный meant pretty, not red. Hence the Red Square and прекрасный - not - G-d forbid! - прекрасивый... So keep calling them Рассель - мягкий знак and everything... After all, Russell the Brit was a fellow traveller - a friend of the Bolsheviks and an enemy of the West. And Russell Crowe does not care.
The Russian language equivalent of the name Lauren is Лорен (pronounced as "Loren").
The Russian language equivalent of the name Dmitry is Dmitriy (Дмитрий).
The Russian language equivalent of the name Ryan is Райан (pronounced 'ra-yahn').
Клиффорд. Pretty much a direct translation of the name.
The Russian language equivalent of the name Mark is Марк (pronounced "mark").
Douwg
Matvey
Бріттні Brittni
Морин Morin
Juana = Ivana (Ивана)
Чарльз (Charl'ze) is how you would spell the name in Russian, if that's what you mean.
Jonny, Johnny