Mating between russians is usually achieved by chasing, head bobbing, biting, ramming, and finally squeeking and honking, always with the male gaping his mouth and maybe drooling.
Just like humans.
It seems that egg laying comes about 4-5 weeks after a "successful" mating. Just because two torts are going at it doesn't mean there will be eggs. And just because there are eggs doesn't mean the eggs are fertile.
If the female seems restless, starts digging holes, and maybe gets aggressive towards the male, then you are likely to find eggs. If the male is perpetually horny and the female seems ready to lay eggs, separate them so the female can lay eggs in peace.
Good luck!