Who is a contract employee? an employee engaged by a contractor to do work for a principal employer. he is paid salary by the contractor. His contributions to ESI or EPF are paid by the contractor. His bonus is paid by the contractor. Then what is the position of principal employer? He only provides a scope for work. There is no direct employer employee relationship between principal employer and the contract labour. Therefore, he cannot claim permanency in principal employer's office or establishment.
At the same time, if the contract is sham or camouflage or just a paper arrangement, but the principal employer decides who should be employed, what should be his wages, and takes disciplinary action and controls and supervises the contract labour, then the picture would be different. If it could be proved that the contract labour is doing the same work which the regular workers are doing, the work is perennial in nature for which worker(s) need regularly or workers can be employed permanently, then the contract becomes sham and in such cases the workers can demand regularisation. This does not apply to genuine contracts.