Drivers door post will give you curb and GVWR numbers. Trailer life publishes each year towing capacity for most every vehicle online.
As a simple guide,
A 1500 series truck can safely handle an average family and a TT up to around 7500 pounds Gross
A 2500 series truck can safely handle family and a TT up to about 12,000 pounds Gross or a fifth wheel up to around 12,000 Gross weight
A 3500SRW truck can handle the average family and a TT up to 14,000 pounds or so. Plus it can handle a fiver up to around 13,000 gross
A 3500 dually will go up from there.
Again, this is a guide line and not set in stone. There are just too many variables to give you more definitive information.
Glossary?
GVWR Gross Vehicle Weight Rating. This is what the mfg rates the vehicle can safely load.
GCWR Gross Combined Weight Rating. Again what the mfg certifies the vehicle and towed load can be.
Dry weight meaningless. No one will ever tow a dry trailer.