I am wiring a 50 amp sub panel in my shop. It comes from a 100 amp sub panel in the garage. I went to the store and got what I thought was #6 3wire with ground. What I got was 6/3 w 10g ground. This new sub is 58 feet from that panel, I measured it exactly.

Do I need to sink a ground rod at the shop and if so how far from the new sub can it be?
If so can I use this cable and just not use the ground? The stamp on the cable says " AWG 6 CU 3 CDR with AWG 10 ground type NM-b 600 volts"

Or do I need to get 6/3 with 6g ground and ground it back the garage sub panel.
Most of the cable run through the garage walls and aprox 7' under a deck in conduit, then the new panel will be just inside the shop wall at the spot were it inters w/ a 1' turn, up.
The shop and Garage are separated only by the deck.
I think I gave all the needed info for a proper answer.

The #10 ground in the 6/3NM is fine. That is correctly sized.

The panel at the shop does need a ground rod since it is in a detached structure. You MUST also use the ground wire in the cable. The ground wire in the cable and a ground rod are two completely different things serving two very different purposes.

One problem I see is that you CANNOT run the NM cable in conduit in a wet location. Even though this conduit is not below grade (an automatic wet location) it is in direct weather and would be considered a wet location, even inside the conduit.

Be sure to not bond the neutral bar in the sub and keep the grounds and neutrals separate. You will probably need an add-on ground bar.

That was fast thank you. But now I'm even more confused. I guess I need to talk to a local electrician and get the exact instructions. And looks like I can't use the cable I got.