This caller is a scammer, saying he is from the U.S. Treasury. Talking about giving you a grant for paying taxes on time and not having a criminal background, do not give him any information and spread the word. I have 3 calls from these people already and they will keep trying.
They buy and sell personal information. Usually on these calls they have access to payday loans or similar documents you might have filed on-line. Sometimes it's just a series of computer generated numbers. Invest in a call blocker and do not pick up on calls you do NOT recognize.