Hello im new to the boards and owning a tub of my own with a couple of questions! Ive always enjoyed using hot tubs at hotels and friends house's and have finally been able to afford one of my own. I have put the tub in the work shop on the side of my garage deemed my "man fort" I have a seperate box in my garage that runs all of the electricity out there. It is attached to a 50a breaker in the house's main box via 10 G wire. There was already a 50A breaker in the garage box that had been used for a air compressor which I have taken out. I ran my 6/3 to my shut off box and then on to my tub. My question is will I be ok to use this configuration being as the box in the garage is wired in with 10g wire or do I need to run a new wire hooking the house to the garage that is 6/3 also. I would appreciate any help you can offer!!

Call your local/town building office and have the electrical inspector come out.

Actually,
Your existing configuration is not even close to code.
You can't have a 50 amp breaker feeding 10 gauge wire. That's a 30 amp maximum (distance dependent also) circuit. National and Local codes will govern this.

What you really need to do is change the feed breaker to the garage to a 20 or 30 amp maximum, and run a new dedicated line out to the shop for the tub. Do not run shop equipment and the hot tub on a sub-panel that will max out in amperage draw on the tub, leaving you nothing else for the garage. IE, if you want both, then get a real serious electrical sub panel installed with proper feed to support in excess of 70-100 amps.

Otherwise, considering a separate run:
Wire size for the tub, again this is distance dependent... The longer the run, the larger the wire size required to safely pass the maximum current load capability of the circuit. The 'typical' 50 amp service to a hot tub will use 6/3 with ground. Be sure to ascertain the maximum current load of your tub. Many will top out somewhere around 35-38 amps, which may require as small a gauge of 8/3 with ground, which is a lot cheaper, and a lot easier to work with.

And for the record, I would always recommend calling a 'licensed electrician', and never a government inspector. Too many municipalities make it their job to intrude into your backyard for no other reason than to prevent you from enjoying your own property. If the need to call a government inspector is properly ascertained, then it is the electrician's responsibility to determine that, pull necessary permits and arrange for inspection. That's the electrician's job.

Thank you for the quick response! I have already ran the 6/3 wire from the sub panel in the garage to my GFCI and then on to my tub. Do you think it would be ok to run a new 6/3 feed wire off my 50 amp in the house out to the sub panel in the garage? Then run the tub like it is off of a 50 amp in the sub panel. Or would I be better off to run the line straight to the tub? It would be easier to run it to the sub box but I want to do what will be the best and safest option. Any advice is greatly appreciated