Dear Sanjay
The definition of contract labour basically says that any person who is working in your premises due to an agreement you have with his direct employer to deliver a result, other than pure sale of goods, is a contract worker. (except those who are there part time and purely admin role).
In view of the above, irrespective of whether he is given a labour supply contract or a job contract, the responsibility and liability is the same for the PE. The thing that will decide the applicability is whether his workers (and not necessary the same worker) regularly work in your premises.
Maharashtra has increased the license applicability from 20 to 50 workers, so he does not need a license. There is a debate (not decided by courts) as to whether the act applies even if the license is not required. So in order to keep yourself safe, ensure that you are verifying his payment of fair wages (and definitely minimum wages), over time at double rate, providing proper leaves and holidays as required under the law, paying all statutory dues.
Further, ensure all safety regulations are followed and if ESIC does not apply, ensure they have workman compensation insurance policy. As Madhu-ji said, ensure that you are not directly involved in controlling or managing the employees of the contractors (other than as required for QC purposes)
If you take care of the above, then you are unlikely to have a problem.