I want to use fibonacci retracement on Bank nifty for Intraday How Can I use it?

I know how to use fibonacci retracement but i cant use it on intraday basis.

what kind of Timeframe shuould i use for this ?

& another problem how can change my Low-High & High-Low as per time going on?

you can check the Varsity Chapter of “The Fibonacci Retracements” for the complete information about fibonacci retracements from the below link