Pf and esic in specialised nature of job

Dear All,
I have a query, we are large establishment and many contractor are working on specialised nature of job, some are working outside the factory premises.
In both the above cases whether PF and ESIC is applicable or not.
If yes, how to emphasize this point to contractors to comply.
Regards

working inside or outside factory premises does not differ the status of employment, as the payment is reflected in accounts of the employer. so the employer has to take all measures to make compliance