Dear Jayaram,
As per how to pay PF of labours, you have to upload the returns on PF site like everyone else and pay it through online challan. For contractual labours PF, you have to monitor as liability & accountability lies with principal employer even for contractual workers. Know PF is based on Basic+Da of that particular month, if the worker is absent throughout the month and have no paid leave then his salary will be zero.hence, PF will be zero.