I tried to solve the problem below but I don’t know if it’s right.
Im finding I2 or the current when SW1 is open. I put a test voltage 1V between the nodes of 8 ohm and 6 ohm resistors so its in parellel with 6-ohm resistor when all independent sources are suppressed. Then I got I2=1/12 A but I'm not sure if it should be negative because of the direction of the current. So I don't know if the norton current is 2.08A or 1.83A. I thought of I2 being negative because I tried to follow the same current flow as I1.
The Rn I got is 12 ohms.