Dear Rajesh

,
The contract manpower can be recruited in two ways:
1) On company rolls but by signing a contract for specified period at the time of joining.
2) Through recruitment consultants who outsource manpower for specific time period.
I find second option better as the consultants themselves manage their PF and ESI norms, thus no record keeping is required by you.
Hope this information will help you.
Regards,
Kopal