The element with 6 protons (atomic number) is carbon (C). Carbon has 6 electrons to balance the 6 protons and maintain electrical neutrality.
You mentioned that the element also has 5 neutrons. However, carbon usually has 6 neutrons. The most common isotope of carbon, Carbon-12 (¹²C), has 6 protons and 6 neutrons. There are other isotopes of carbon with different numbers of neutrons, such as Carbon-13 (¹³C) with 6 protons and 7 neutrons, and Carbon-14 (¹⁴C) with 6 protons and 8 neutrons.
If an element has 6 protons, 6 electrons, and 5 neutrons, it would not be a stable isotope of carbon.