It isn't even remotely certain whether they will hold any elections at all. They're just talking about holding elections because the US is pressuring them right now, but imo there is no way the regime has any intentions of actually holding them.
They seem to be using this as just another stalling tactic, and hoping they can somehow trick Russia into giving them a ceasefire to regroup, rearm and entrench by claiming they can't hold elections without a ceasefire. They will say they can't organize elections without at least six months of ceasefire beforehand.
Which is nonsense of course, and even if they did get that time, i am almost certain they would just come up with some excuse to cancel the elections or delay them even further. And of course they already announced that, even if there is a ceasefire, they would not lift martial law, and that makes it incredibly easy to rig the election by just arresting the opposition by claiming they are working with the enemy. Not to mention they would have armed Nazi groups at every polling station, and probably Nazis "counting" the votes.
They would also 100% exclude the millions of Ukrainian refugees living in Russia now from voting. As long as this regime is in power any "election" would be a farce.
But none of this matters because Russia isn't going to fall for it regardless. I believe someone in the Russian government recently said they'd give them at most two days of ceasefire for any elections. Everyone with a brain can see that this whole thing is just another desperate ploy, it's all a propaganda spectacle directed at Western audiences.
And by the way, their talk about needing to hold a referendum for Ukrainians to decide if they should "give away" the Donbass is also a total joke, because a) it makes no difference to Russia what the outcome would be even if the referendum was not rigged, as this matter is already settled as far as the Russians are concerned - the four new Russian oblasts already had referendums - and b) any referendum organized by the Kiev regime would exclude the actual people of the Donbass itself who are now overwhelmingly Russian citizens, making the whole thing meaningless.