Thats a very open ended question. This all depends on how long is the trailer? How much does the trailer empty weight? How far are you really needing to transport your material? Over level ground or up/down a slope?
I understand what your wanting to do here, as i know many people move trailers and things around using the 3pt instead of drawbar, its so much easier, i get it. Your 3pt is rated i think around 2300lbs @ 24" beyond where the lift cam/shaft is. I think this is the spec you are going to be limited by, i wouldnt worry so much as to the weight you can tow vs if you are able to raise your 3pt. Or not. If it raises, it should pull it, if it dont raise then adjust what your carrying. Im still interested in answers to my questions though.
And iut of curiosity, If I said you can tow 6,000 pounds safely with your tractor how do you know when your loaded to 6000lbs ?