What is my liability if my commercial vehicle met with an accident?

We would need more information to ascertain the losses that will be borne by you like against whom has the FIR been registered - it is against the driver of the truck or the driver of the car? The vehicle against which the FIR is registered is the offending vehicle and the liability to pay compensation rests with the registered owner of the offending vehicle and in case the offending vehicle is insured, then the insurance company is liable to indemnify the insured and pay compensation to the claimants as per the Terms and Conditions of the Insurance Policy.

Now coming to the facts mentioned by you, if your vehicle was having a valid permit and the driver of your vehicle was having a valid Driving License at the time of the accident, no liability can be fastened against the registered owner and the compensation if any, is to be paid by the insurance company.

Even otherwise, as you are not the registered owner of the offending vehicle, you are not liable to pay any compensation whatsoever. However, it is the contract between you and the registered owner that will define your liability, if any.