You mentioned Quranic baby name Arhab means (intelligent, open minded, gracious) but i search meaning found in google Arhab means Terrorism in Arabic language.

So, Please explain, In which surah Arhab mentioned in Quran and what is exact meaning

What is on the site is correct, and what you say is correct as well, because Arhab could refer to two different names. In Arabic their spelling is different, but in English they are spelled the same.

The Arhab on the site is أرحب, derived from رحب Quranic root. Arhab itself is not used in the Quran, but its root is used in a number of places, such as 9:25, in the form "rahubat", which means breadth, vastness: "Indeed, God has helped you on many occasions. On the day of Hunayn, when you took pride in your great numbers, they proved of no avail to you—for the earth, despite all its vastness, became [too] narrow for you and you turned back, in retreat."

Arhab means very vast, or open, and when used to describe a person it means intelligent, open minded, charitable.