i started the the quest returning hope from camp forlon hope and the legion took over helios one and helios one was the quest marker so can any oone help me on how to get the quest done or ncr to move back into helios one?

I'm guessing that the reason why the Legion occupied Helios One is because you armed Archimedes and killed all of the NCR inside the base. You are meant to meet the named NCR officer outside the doors of Helios One and she'll tell you that they didn't get the shipment, a tracking device was attached to the supplies and you'll get another quest marker that shows a point roughly in between Helios One and Forlorn Hope which is where the supplies are.

Obviously the officer your supposed to meet is dead so the only way to continues with the quest is to go straight to picking up the supplies. They are located directly north of the northeast corner of the Southern Nevada Wind Farm.

If you are on the PC then http://directly%20north%20of%20the%20northeast%20corner%20of%20the%20Southern%20Nevada%20Wind%20Farm. could help you. It's a console command that will place the supplies directly into your inventory. The link goes to the bugs section of the Restoring Hope quest, the top bug is yours actually.

Good luck and welcome to the forums.

Half way between Helios and Forlorn Hope the bodies and shipment will be found.
Ignore your marker since the "marked" person is obviously dead, going directly to the shipments location may be your only hope.
Good luck with it.

Yeah this^. restoring hope is one of the best and funnest quest out there. Love it,

Cheers