We know that the number of proton and number of electrons are same as the atomic number in case of neutral atom while the number of neutrons can be determined by the subtracting the number of protons to the mass number.

Therefore,

Number of proton and electrons in ${}_6{}^{13}\mathrm{C}$ is $6$

Number of neutrons in ${}_6{}^{13}\mathrm{C}$ $= 13-6 = 7$