A good rule of thumb i like to use, is multiply the payout by 10, that is the longest red streak you SHOULD see.
It could be longer, but the odds of it being longer than 10x payout is pretty rare, maybe like one in a million rolls.
I have placed 2 millions bets so far, and i have only gone ove the 10x payout rule twice
So to answer your question, on 990x you should expect to see a loss streak of 9900 rolls, the 2 times i have rolled more than 10x payout have always hit in the next 1x payout, so for you, it should hit in the next 990-1500 rolls