This simple datapath is of a single-cycle nature. The instruction begins with the PC.
JR Instruction

The Jump Register instruction causes the PC to jump to the contents of the first source register.

It's syntax is:
JR $first source register's address

The sample JR instruction demonstrated in the datapath above is JR $13.

The instruction's equivalent in binary is:

Information on the content of the registers used:
Register's Address Register's Address
(Binary)
Register's Value Register's Value
(Hexadecimal)
$13 01101