Statistically how to find overbought and oversold condition of stocks?.

Statistically how to find overbought and oversold condition of stocks.
Name some prediction methods available in R?.

Welcome to the world of R email lists - a different animal than any
other on the web...

Anyway, Investopedia has some fairly straight forward answers to your
question. Using this description you could use anything like RSI,
stochastics, etc.

http://www.investopedia.com/terms/o/overbought.asp

Hope this helps,
Mark