i would like to ask these two questions:-1 - what is the candle stick type that i must see when an over bought market fall down,
2-what is the candle stick type that i must see when an over sold market begins to raise up
Overbought and oversold conditions are normally shown by an indicator such as RSI. These are not highly reliable but might help if your strategy demands an indicator of this sort. Its not normally profitable to simply buy if the indicator says oversold and sell immediately it changes to overbought.
Individual candlesticks are also not highly reliable ways of seeing oversold/overbought market conditions. Some candlestick patterns do show a reversal is about to occur. Research things like hammers, shooting stars, outside key reversals, etc. Look at work by Steve Nison and Thomas Bulkowski.