From the RAG we can make the necessary matrices.
Allocation

$R1$ 
$R2$ 
$R3$ 
$P0$ 
$1$ 
$0$ 
$1$ 
$P1$ 
$1$ 
$1$ 
$0$ 
$P2$ 
$0$ 
$1$ 
$0$ 
$P3$ 
$0$ 
$1$ 
$0$ 
Future Need

$R1$ 
$R2$ 
$R3$ 
$P0$ 
$0$ 
$1$ 
$1$ 
$P1$ 
$1$ 
$0$ 
$0$ 
$P2$ 
$0$ 
$0$ 
$1$ 
$P3$ 
$1$ 
$2$ 
$0$

$\text{Total}=(2\quad 3\quad 2)$
$\text{Allocated}=(2\quad 3\quad 1)$
$\text{Available}=\text{Total} \text{Allocated} =(0\quad 0\quad 1)$
$P2 s$ need $(0\quad 0\quad 1 )$ can be met
And it releases its held resources after running to completion
$A=(0\quad 0\quad 1)+(0\quad 1\quad 0)=(0\quad 1\quad 1)$
$P0 s$ need $(0\quad 1\quad 1 )$ can be met
and it releases
$A=(0\quad 1\quad 1)+(1\quad 0\quad 1)=(1\quad 1\quad 2)$
$P1$ needs can be met $(1\quad 0\quad 0)$
and it releases
$A=(1\quad 1\quad 2)+(1\quad 1\quad 0)=(2\quad 2\quad 2)$
$P3 s$ need can be met
So, the safe sequence would be $P2P0 P1 P3.$