Practical wisdom and the way we teach in the UK is that if you do not know the weight of the load, do not try to lift it but find the paperwork or something that tells you the weight first.
The issue of course being that the truck might lift the load six inches from the floor and you think it's okay, but as you lift higher the capacity reduces and you could end up tipping the truck and load if the weight is more than the truck can handle.

Thank u for the response yes I'm handling a forklift counterbalanced.
If I'm unable to do calculations for some reason and there is no scale or label on the pallet should I do a test lift.

I think the answers are:

1. Yes. The truck has a Rated Capacity of 7500 kg at a Load centre of 850 mm.
The container is 1175mm length (presuming picked up in this direction, so Load centre would be 588 mm) and total weight is only 1700 kg.

2. No. Gross weight is 8500 kg. (Container = 2500 kg and Load is 6000 kg)

3. 4700 mm (Not a Yes or No answer)

Am presuming you are operating a Container Handling truck?