Ok so here is the deal. My dad hadd ordered a small batch of flame moss from a seller on ebay (no one here) and it came pretty much brown and ugly and dead looking. It was super cheap with free shipping which is why he figured he would try since he knew I was kinda looking into it. Well I have it in a little tupperware container right now hoping that it will spring back to life a little bit since some of it looks slightly more green. I refuse to contact seller since it was so cheap and seller had bad reviews. (My dad was trying so hard to be nice) So is there any way I can help whats left come back to life? Should I put it in the tank?
Put in an airstone for water flow. Stagnant water is not good for moss if it's tank water. Good flow will work miracles! I'd clip off all the obviously dead parts and just to to work with the green bits, even if they're small.
I'd just search for new moss through the swap and shop, sure someone has it out there. It'll take forever to revive. Definitely contact seller as you paid for it, you should get what you paid for. Or try growing it emmersed in the tuppleware.
All mosses are very resilient but do like cool water with CO2 and tons of light if you can provide it, after you wash it, trim it, and get light to the green areas it should start to turn around. You can also take a portion of it and chop it finely and then rub it onto the rock/wood you like and then place in a covered tank with a half inch of water, like a dry start tank, after 10 days you will have moss growing on the item, it will still require light in this covered tank, research the dry start method/DSM.
The same happened to me, I had a few flame mosses shipped and they looked all brown and tiny, nothing like the ones you see in pictures. Three weeks under strong light with good filtration, cool water, and co2 did the trick. They now look great! I attach them to rocks with moss cotton and use them as background. They grow upwards nice and bushy.