These are both reliable technical indicators, but the RSI appears to work well in trending markets while stochastic works well in sideways markets. They tend to plot similar data, but how they calculate that data is different and it may impact which one you prefer using.
When you plot these on your chart, you will find that they run from 0 to 100, indicating overbought when near 100 and oversold with nearing 0. The stochastic RSI uses 0 to 1 and another below .2 is at the low end of trading and .8 is at the high end.
With that in mind, if you have not read the individual indicators and know what they mean, here at Macroaxis we have information on each tool and it is highly recommended that you understand what each of them does. Together, they can be a powerful tool and allow you to time your buys and sells better, leaving you with a potentially greater return on your investments.
Be sure to test this on a demo account first and if you are still searching for more information, the Internet has many articles on this tool as it is widely known and used throughout the investing and trading community.