Applicability of Industrial Disputes Act and conciliation machinery to the contract employees of Autonomous bodies

Whether Industrial Disputes Act and the conciliation machineries.. i.e Labour Commissioner(Central) is applicable to the autonomous bodies under the Central Government

Here the permanent employees are approaching CAT for their grievances

However, the problem is with the employees ,who are employed on a fixed term employment(on direct contract with the said autonomous body).

Need to know, whether they shall approach CAT or Labour Commissioners(Central) for their grievances.