Permanent job

Nowadays many jobs are outsourced. Some agencies take the work being outsourced and employ people themselves to do such outsourced work. In such a case, the employee of the outsourced agency has no connection with the original whose work he is doing. 

Similarly, in your case, you are writing that you are working with a contractor, who may be handling the work outsourced by PSU and for doing such work hired you. Please verify who gave you appointment letter (if at it is given). If the Contractor has given the appointment letter , you are the employee of the Contractor and not that of the PSU.

You can move petition for conferment of permanant status to workment act 1981

You have been employed by Contractor, who was an agent of PSU and PSU has not employed you, you do not have relationship with PSU to demand any benefit from them.  If PSU recruits and gives such notification, you may come in that process and prevail upon them during interview for consideration of your case in view of your past experience.

You do not have any rights on PSU.

So so far you have not gone to court.