To go for a direct Answer 'No'.
Your berth may be probably allotted to some one else till Erode. or may not be allotted to anyone else.
My suggestion will be take a second class ticket from PGT to Erode and directly go to your berth. If it is vacant you can occupy else adjust somewhere. If TTE comes worst case he will ask you to leave for second class, which I hope won't reach that level.