Depending on your location, Google may be required to collect tax-related information from you. If you have to provide your tax information to Google, you can do so from the Google payments center. Not everyone is required to provide tax information. 
If you are not understanding what to do you have to press Learn more option on this tab. Google adsense support has given all the FAQ. You can learn from here or ask to any experienced person about this tax information. Don't take unnecessary action.