Answer
False
Work Step by Step
Let us take an example: $A=\begin{bmatrix}
0&1 \\
0&0
\end{bmatrix}$
This implies that $Rank(A)=1$ and so, the Rank-Nullity Theorem gives: $nullity(A)=1$.
This means that the number of zerors appearing in the main diagonal of the matrix is equal to$2$ which is not equal to $1$.
Hence, the given statement is false.