Dear Hiren Rohit,
What is the nature of your industry? What type of work the contractor will do? Will it be a service contract or work contract? What is the level of exposure of hazards to the workers employed by the contractor?
You can issue the PO to the contractor clearly mentioning the terms and conditions of the PO. You can add a clause of indemnity in your contract provided it is a works contract. For example, in a multi-storeyed building, the owners' association of the builds awards contract for the replacement of the lift. This is a work contract and nothing wrong per se with inserting indemnity clause.
For the service contract, whether the contractor will accept the indemnity clause that remains to be seen. For example, you have awarded a contract to a security agency to provide the security to your business premises. This is an ongoing work and exposure to some hazard is always there. Should you indemnify yourself against the injuries that the security personnel may sustain in case of fire or an incident of theft?
Nothing wrong with indemnifying one's company nevertheless, some amount of ownership for the payment of compensation has to be taken against the loss of life or the injuries at the workplace. While running a business, one cannot wash off one's hands completely.
Thanks,
Dinesh Divekar