Nifty at all time high should i invest?

As RSI is very high so i exited from all the stocks and will buy when RSI is about 30-35 and it gives signal to buy. I hope nify will touch 20300 in coming days.
There is a saying in stock market "BUY ON RUMOUR AND SELL ON NEWS" so sold everything as FED news is out
disclaimer:- I am still a learner and will always be