It depends on how old your tortoise is. Babies need to be soaked daily and the number decreases as they grow older. My russians never use their water dish so i soak them 3-4 times a day. This is because they came to me fairly dehydrated already. Many just soak them twice a week. Or none at all if they use their water dish often.
My russians are 5.5" and 3.5" by the way. And i soak them for 15-20 minutes.
Daily soaks for older tortoises wont harm them either
There's no hard and fast 'rule'. If you search for answers on this site, you'll come up with the gamut of routines.
I soak my Hermann's 3X a week. I start with water that is about 95 F/ 35 C. She soaks for 15 minutes. By then the water has cooled a bit, which is fine.
I keep her substrate moist. I have also seen her drink from her water bowl, so I know she'll drink if thirsty.
If your Russian tortoise is a store-bought tortoise it is probably close to, if not full grown. In my opinion, full grown tortoises can hydrate themselves. Provide a waterer and keep fresh water in it. I like to place it along the fence-line so they walk through it in their wanderings. I don't soak any of my grown tortoises.
When I have a tortoise in the house, babies or ill tortoises, I understand that the lights and heat tend to dry the animals out quickly. So for in-the-house tortoises, I soak them daily for about 15 minutes each time. BUT I have no occasion to have healthy, full grown tortoises in the house. These are only babies or ill tortoises.
I am a firm believer that healthy, full grown tortoises do better outside and should be set up outside in a safe and secure yard.