2007 04th Oct . RSI was 87.05. Market Stayed up 98 days after that till 9th Jan 2008. After it gave Sharp correction(lehman brothers collapse) of 30% in 10 trading days. total correction of 64% till Nov 2008
2021 Sep, 1st time Nifty RSI touched 87 after 2007 .
Just for Reference. I do not hold any view based on this.