If I understand correctly, you have a set of .IFO, .BUP and .VOB files, right?
If these files can fit on a single layer disc, and you are using nero, you only need to create a new DVD video (see pic) and insert all ifo, bup and vob files in the VIDEO_TS folder.
Nero will create automatically that folder.
If all files are too large and doesn't fit on a single layer disc, you have two possibilities:
1) burn on a DL disc
2) Use DVD Shrink to compress the movie.
To compress the movie with shrink, simply select the "Open files" button, select stuff you want to remove unchecking corresponding boxes (for example foreign languages), and then press the "Backup" button. Select the folder where you want to save files, and wait until shrink end work.
Finally, burn all resulting files in the VIDEO_TS folder as in the previous example.