Question

what is the plural form of he?

Answer 1

"they" is the plural form of he and she both.

Answer 2

$\large\color{purple}\mathcal{Hello\:Friend}$

The plural form of $\large\color{blue}\texttt{`He'}$ is $\large\color{blue}\texttt{`They'}$.

$\large\color{orange}\mathcal{-**-}$And it is the same for $\large\color{purple}\mathcal{'She'}$ also.$\large\color{orange}\mathcal{-**-}$